tools: fix mq_open_tests compile warnings

Fix several compile warnings - these are repeats like the ones
below:

gcc -O2 -lrt mq_open_tests.c -o mq_open_tests
mq_open_tests.c: In function ‘main’:
mq_open_tests.c:295:2: warning: format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘rlim_t’ [-Wformat=]
  printf("\tRLIMIT_MSGQUEUE(soft):\t\t%d\n", saved_limits.rlim_cur);
  ^
mq_open_tests.c: In function ‘shutdown’:
mq_open_tests.c:83:9: warning: ignoring return value of ‘seteuid’, declared with attribute warn_unused_result [-Wunused-result]
  seteuid(0);
Signed-off-by: NShuah Khan <shuah.kh@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

tools/testing/selftests/mqueue/mq_open_tests.c

@@ -80,7 +80,8 @@ void shutdown(int exit_val, char *err_cause, int line_no)
 	if (in_shutdown++)
 		return;
 
-	seteuid(0);
+	if (seteuid(0) == -1)
+		perror("seteuid() failed");
 
 	if (queue != -1)
 		if (mq_close(queue))
@@ -292,8 +293,10 @@ int main(int argc, char *argv[])
 	/* Tell the user our initial state */
 	printf("\nInitial system state:\n");
 	printf("\tUsing queue path:\t\t%s\n", queue_path);
-	printf("\tRLIMIT_MSGQUEUE(soft):\t\t%d\n", saved_limits.rlim_cur);
-	printf("\tRLIMIT_MSGQUEUE(hard):\t\t%d\n", saved_limits.rlim_max);
+	printf("\tRLIMIT_MSGQUEUE(soft):\t\t%ld\n",
+		(long) saved_limits.rlim_cur);
+	printf("\tRLIMIT_MSGQUEUE(hard):\t\t%ld\n",
+		(long) saved_limits.rlim_max);
 	printf("\tMaximum Message Size:\t\t%d\n", saved_max_msgsize);
 	printf("\tMaximum Queue Size:\t\t%d\n", saved_max_msgs);
 	if (default_settings) {
@@ -308,8 +311,8 @@ int main(int argc, char *argv[])
 	validate_current_settings();
 
 	printf("Adjusted system state for testing:\n");
-	printf("\tRLIMIT_MSGQUEUE(soft):\t\t%d\n", cur_limits.rlim_cur);
-	printf("\tRLIMIT_MSGQUEUE(hard):\t\t%d\n", cur_limits.rlim_max);
+	printf("\tRLIMIT_MSGQUEUE(soft):\t\t%ld\n", (long) cur_limits.rlim_cur);
+	printf("\tRLIMIT_MSGQUEUE(hard):\t\t%ld\n", (long) cur_limits.rlim_max);
 	printf("\tMaximum Message Size:\t\t%d\n", cur_max_msgsize);
 	printf("\tMaximum Queue Size:\t\t%d\n", cur_max_msgs);
 	if (default_settings) {
@@ -454,7 +457,12 @@ int main(int argc, char *argv[])
 	else
 		printf("Queue open with total size > 2GB when euid = 0 "
 		       "failed:\t\t\tPASS\n");
-	seteuid(99);
+
+	if (seteuid(99) == -1) {
+		perror("seteuid() failed");
+		exit(1);
+	}
+
 	attr.mq_maxmsg = cur_max_msgs;
 	attr.mq_msgsize = cur_max_msgsize;
 	if (test_queue_fail(&attr, &result))