selftests: mqueue: return Kselftest Skip code for skipped tests

When mqueue test is skipped because of unmet dependencies and/or
unsupported configuration, it exits with error which is treated as
a fail by the Kselftest framework. This leads to false negative
result even when the test could not be run.

Change it to return kselftest skip code when a test gets skipped to
clearly report that the test could not be run.

Change it to use ksft_exit_skip() when the test is skipped.

Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>

tools/testing/selftests/mqueue/mq_open_tests.c

@@ -33,6 +33,8 @@
 #include <mqueue.h>
 #include <error.h>
 
+#include "../kselftest.h"
+
 static char *usage =
 "Usage:\n"
 "  %s path\n"
@@ -262,12 +264,10 @@ int main(int argc, char *argv[])
 		}
 	}
 
-	if (getuid() != 0) {
-		fprintf(stderr, "Not running as root, but almost all tests "
+	if (getuid() != 0)
+		ksft_exit_skip("Not running as root, but almost all tests "
 			"require root in order to modify\nsystem settings.  "
 			"Exiting.\n");
-		exit(1);
-	}
 
 	/* Find out what files there are for us to make tweaks in */
 	def_msgs = fopen(DEF_MSGS, "r+");