Fix compile warning in main.c.

git-svn-id: http://svn.fedorahosted.org/svn/corosync/trunk@2057 fd59a12c-fef9-0310-b244-a6a79926bd2f

exec/main.c

@@ -538,7 +538,7 @@ static int corosync_security_valid (int euid, int egid)
 
 static int corosync_service_available (unsigned int service)
 {
-	return (ais_service[service]);
+	return (ais_service[service] != NULL);
 }
 
 static int corosync_response_size_get (unsigned int service, unsigned int id)