tools/testing/selftests/ipc/msgque.c: improve error handling when not running as root

The test fails in the middle when it is not run as root while accessing
/proc/sys/kernel/msg_next_id.  Changed it to check for root at the
beginning of the test and exit if not root.
Signed-off-by: Shuah Khan <shuah.kh@samsung.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Cc: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tools/testing/selftests/ipc/msgque.c

@@ -193,6 +193,11 @@ int main(int argc, char **argv)
 	int msg, pid, err;
 	struct msgque_data msgque;
 
+	if (getuid() != 0) {
+		printf("Please run the test as root - Exiting.\n");
+		exit(1);
+	}
+
 	msgque.key = ftok(argv[0], 822155650);
 	if (msgque.key == -1) {
 		printf("Can't make key\n");