perf test: Keep test result clean if '-v' not set

According to [1], 'perf test' should avoid output too much information
if '-v' is not set, only 'Ok', 'FAIL' or 'Skip' need to be printed.

This patch removes several messages sent directly to stderr to make
the output clean.

Before this patch:

# perf test dummy
23: Test using a dummy software event to keep tracking : (not supported) Ok

After this patch:

# perf test dummy
23: Test using a dummy software event to keep tracking : Skip

[1] http://lkml.kernel.org/r/[e-mail]

Signed-off-by: Wang Nan <[e-mail]>
Acked-by: Namhyung Kim <[e-mail]>
Tested-by: Arnaldo Carvalho de Melo <[e-mail]>
Cc: Zefan Li <[e-mail]>
Cc: [e-mail]
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/tests/attr.c

···
 	    !lstat(path_perf, &st))
 		return run_dir(path_dir, path_perf);
 
-	fprintf(stderr, " (omitted)");
-	return 0;
+	return TEST_SKIP;
 }

tools/perf/tests/code-reading.c

···
 	case TEST_CODE_READING_OK:
 		return 0;
 	case TEST_CODE_READING_NO_VMLINUX:
-		fprintf(stderr, " (no vmlinux)");
+		pr_debug("no vmlinux\n");
 		return 0;
 	case TEST_CODE_READING_NO_KCORE:
-		fprintf(stderr, " (no kcore)");
+		pr_debug("no kcore\n");
 		return 0;
 	case TEST_CODE_READING_NO_ACCESS:
-		fprintf(stderr, " (no access)");
+		pr_debug("no access\n");
 		return 0;
 	case TEST_CODE_READING_NO_KERNEL_OBJ:
-		fprintf(stderr, " (no kernel obj)");
+		pr_debug("no kernel obj\n");
 		return 0;
 	default:
 		return -1;

tools/perf/tests/keep-tracking.c

···
 	evsel->attr.enable_on_exec = 0;
 
 	if (perf_evlist__open(evlist) < 0) {
-		fprintf(stderr, " (not supported)");
-		err = 0;
+		pr_debug("Unable to open dummy and cycles event\n");
+		err = TEST_SKIP;
 		goto out_err;
 	}
 

tools/perf/tests/llvm.c

···
 static int test__bpf_parsing(void *obj_buf __maybe_unused,
 			     size_t obj_buf_sz __maybe_unused)
 {
-	fprintf(stderr, " (skip bpf parsing)");
+	pr_debug("Skip bpf parsing\n");
 	return 0;
 }
 #endif
···
 	 * and clang is not found in $PATH, and this is not perf test -v
 	 */
 	if (verbose == 0 && !llvm_param.user_set_param && llvm__search_clang()) {
-		fprintf(stderr, " (no clang, try 'perf test -v LLVM')");
+		pr_debug("No clang and no verbosive, skip this test\n");
 		return TEST_SKIP;
 	}
 
···
 	err = llvm__compile_bpf("-", &obj_buf, &obj_buf_sz);
 
 	verbose = old_verbose;
-	if (err) {
-		if (!verbose)
-			fprintf(stderr, " (use -v to see error message)");
-		return -1;
-	}
+	if (err)
+		return TEST_FAIL;
 
 	err = test__bpf_parsing(obj_buf, obj_buf_sz);
 	free(obj_buf);

tools/perf/tests/switch-tracking.c

···
 
 	/* Third event */
 	if (!perf_evlist__can_select_event(evlist, sched_switch)) {
-		fprintf(stderr, " (no sched_switch)");
+		pr_debug("No sched_switch\n");
 		err = 0;
 		goto out;
 	}
···
 	}
 
 	if (perf_evlist__open(evlist) < 0) {
-		fprintf(stderr, " (not supported)");
+		pr_debug("Not supported\n");
 		err = 0;
 		goto out;
 	}