cluster_fatal() exit code should not indicate success.

cluster_fatal() logs a fatal event and then exits with 0.  This seems
wrong.  Sometimes command like "net" use this code and return
incorrect empty output but then exit with 0.

This simply changes the exit code to 1.

Signed-off-by: Martin Schwenke <martin@meltin.net>

source3/lib/ctdbd_conn.c

@@ -58,7 +58,7 @@ static void cluster_fatal(const char *why)
 	   a core file. We need to release this process id immediately
 	   so that someone else can take over without getting sharing
 	   violations */
-	_exit(0);
+	_exit(1);
 }
 
 /*