selftests: breakpoints: step_after_suspend_test use ksft_* var arg msg api

Use ksft_* var arg msg to include strerror() info. in test output and
simplify test_result and exit_* using var arg msg api.

Signed-off-by: Shuah Khan <[e-mail]>

tools/testing/selftests/breakpoints/step_after_suspend_test.c

···
 	CPU_ZERO(&set);
 	CPU_SET(cpu, &set);
 	if (sched_setaffinity(0, sizeof(set), &set) != 0) {
-		perror("sched_setaffinity() failed");
+		ksft_print_msg("sched_setaffinity() failed: %s\n",
+			strerror(errno));
 		_exit(1);
 	}
 
 	if (ptrace(PTRACE_TRACEME, 0, NULL, NULL) != 0) {
-		perror("ptrace(PTRACE_TRACEME) failed");
+		ksft_print_msg("ptrace(PTRACE_TRACEME) failed: %s\n",
+			strerror(errno));
 		_exit(1);
 	}
 
 	if (raise(SIGSTOP) != 0) {
-		perror("raise(SIGSTOP) failed");
+		ksft_print_msg("raise(SIGSTOP) failed: %s\n", strerror(errno));
 		_exit(1);
 	}
 
···
 	pid_t wpid;
 
 	if (pid < 0) {
-		perror("fork() failed");
+		ksft_print_msg("fork() failed: %s\n", strerror(errno));
 		return false;
 	}
 	if (pid == 0)
···
 
 	wpid = waitpid(pid, &status, __WALL);
 	if (wpid != pid) {
-		perror("waitpid() failed");
+		ksft_print_msg("waitpid() failed: %s\n", strerror(errno));
 		return false;
 	}
 	if (!WIFSTOPPED(status)) {
-		printf("child did not stop\n");
+		ksft_print_msg("child did not stop: %s\n", strerror(errno));
 		return false;
 	}
 	if (WSTOPSIG(status) != SIGSTOP) {
-		printf("child did not stop with SIGSTOP\n");
+		ksft_print_msg("child did not stop with SIGSTOP: %s\n",
+			strerror(errno));
 		return false;
 	}
 
 	if (ptrace(PTRACE_SINGLESTEP, pid, NULL, NULL) < 0) {
 		if (errno == EIO) {
-			ksft_exit_skip("ptrace(PTRACE_SINGLESTEP) "
-				"not supported on this architecture");
+			ksft_exit_skip(
+				"ptrace(PTRACE_SINGLESTEP) not supported on this architecture: %s\n",
+				strerror(errno));
 		}
-		perror("ptrace(PTRACE_SINGLESTEP) failed");
+		ksft_print_msg("ptrace(PTRACE_SINGLESTEP) failed: %s\n",
+			strerror(errno));
 		return false;
 	}
 
 	wpid = waitpid(pid, &status, __WALL);
 	if (wpid != pid) {
-		perror("waitpid() failed");
+		ksft_print_msg("waitpid() failed: $s\n", strerror(errno));
 		return false;
 	}
 	if (WIFEXITED(status)) {
-		printf("child did not single-step\n");
+		ksft_print_msg("child did not single-step: %s\n",
+			strerror(errno));
 		return false;
 	}
 	if (!WIFSTOPPED(status)) {
-		printf("child did not stop\n");
+		ksft_print_msg("child did not stop: %s\n", strerror(errno));
 		return false;
 	}
 	if (WSTOPSIG(status) != SIGTRAP) {
-		printf("child did not stop with SIGTRAP\n");
+		ksft_print_msg("child did not stop with SIGTRAP: %s\n",
+			strerror(errno));
 		return false;
 	}
 
 	if (ptrace(PTRACE_CONT, pid, NULL, NULL) < 0) {
-		perror("ptrace(PTRACE_CONT) failed");
+		ksft_print_msg("ptrace(PTRACE_CONT) failed: %s\n",
+			strerror(errno));
 		return false;
 	}
 
 	wpid = waitpid(pid, &status, __WALL);
 	if (wpid != pid) {
-		perror("waitpid() failed");
+		ksft_print_msg("waitpid() failed: %s\n", strerror(errno));
 		return false;
 	}
 	if (!WIFEXITED(status)) {
-		printf("child did not exit after PTRACE_CONT\n");
+		ksft_print_msg("child did not exit after PTRACE_CONT: %s\n",
+			strerror(errno));
 		return false;
 	}
 
···
 	power_state_fd = open("/sys/power/state", O_RDWR);
 	if (power_state_fd < 0)
 		ksft_exit_fail_msg(
-			"open(\"/sys/power/state\") failed (is this test running as root?)");
+			"open(\"/sys/power/state\") failed (is this test running as root?)\n");
 
 	timerfd = timerfd_create(CLOCK_BOOTTIME_ALARM, 0);
 	if (timerfd < 0)
-		ksft_exit_fail_msg("timerfd_create() failed");
+		ksft_exit_fail_msg("timerfd_create() failed\n");
 
 	spec.it_value.tv_sec = 5;
 	err = timerfd_settime(timerfd, 0, &spec, NULL);
 	if (err < 0)
-		ksft_exit_fail_msg("timerfd_settime() failed");
+		ksft_exit_fail_msg("timerfd_settime() failed\n");
 
 	if (write(power_state_fd, "mem", strlen("mem")) != strlen("mem"))
-		ksft_exit_fail_msg("entering suspend failed");
+		ksft_exit_fail_msg("Failed to enter Suspend state\n");
 
 	close(timerfd);
 	close(power_state_fd);
···
 	cpu_set_t available_cpus;
 	int err;
 	int cpu;
-	char buf[10];
 
 	ksft_print_header();
 
···
 
 	err = sched_getaffinity(0, sizeof(available_cpus), &available_cpus);
 	if (err < 0)
-		ksft_exit_fail_msg("sched_getaffinity() failed");
+		ksft_exit_fail_msg("sched_getaffinity() failed\n");
 
 	for (cpu = 0; cpu < CPU_SETSIZE; cpu++) {
 		bool test_success;
···
 			continue;
 
 		test_success = run_test(cpu);
-		sprintf(buf, "CPU %d", cpu);
 		if (test_success) {
-			ksft_test_result_pass(buf);
+			ksft_test_result_pass("CPU %d\n", cpu);
 		} else {
-			ksft_test_result_fail(buf);
+			ksft_test_result_fail("CPU %d\n", cpu);
 			succeeded = false;
 		}
 	}