proc: return exit code 4 for skipped tests

Test harness uses 4 for SKIP, not 2.

Link: http://lkml.kernel.org/r/20190108193108.GA12259@avx2
Signed-off-by: Alexey Dobriyan <[e-mail]>
Cc: Shuah Khan <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

tools/testing/selftests/proc/proc-loadavg-001.c

···
 
 	if (unshare(CLONE_NEWPID) == -1) {
 		if (errno == ENOSYS || errno == EPERM)
-			return 2;
+			return 4;
 		return 1;
 	}
 

tools/testing/selftests/proc/proc-self-map-files-002.c

···
 	p = mmap((void *)va, PAGE_SIZE, PROT_NONE, MAP_PRIVATE|MAP_FILE|MAP_FIXED, fd, 0);
 	if (p == MAP_FAILED) {
 		if (errno == EPERM)
-			return 2;
+			return 4;
 		return 1;
 	}
 

tools/testing/selftests/proc/proc-self-syscall.c

···
 	fd = open("/proc/self/syscall", O_RDONLY);
 	if (fd == -1) {
 		if (errno == ENOENT)
-			return 2;
+			return 4;
 		return 1;
 	}
 

tools/testing/selftests/proc/proc-self-wchan.c

···
 	fd = open("/proc/self/wchan", O_RDONLY);
 	if (fd == -1) {
 		if (errno == ENOENT)
-			return 2;
+			return 4;
 		return 1;
 	}
 

tools/testing/selftests/proc/read.c

···
 
 	d = opendir("/proc");
 	if (!d)
-		return 2;
+		return 4;
 	f(d, 0);
 	return 0;
 }