scripts: return non zero if save_mountpoint() fails

In such case, we must not proceed: without saved mountpoint, we risk
losing data when restarting automount service (think about tmpfs).
Currently, zero will be returned as exit status of preceeding echo.
https://jira.sw.ru/browse/PSBM-44207Signed-off-by: Eugene Kolomeetz <klm@virtuozzo.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

scripts/systemd-autofs-restart.sh

@@ -96,7 +96,7 @@ function save_mountpoint {
 	bindmount=$($JOIN_CT mktemp -d)
 	if [ -z "$bindmount" ]; then
 		echo "Failed to create temporary directory"
-		return
+		return 1
 	fi
 
 	# No need to unmount fs on top of autofs: