xfs: return errors in xfs_fs_sync_fs

Now that the VFS will do something with the return values from
->sync_fs, make ours pass on error codes.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian Brauner <brauner@kernel.org>

fs/xfs/xfs_super.c

@@ -735,6 +735,7 @@ xfs_fs_sync_fs(
 	int			wait)
 {
 	struct xfs_mount	*mp = XFS_M(sb);
+	int			error;
 
 	trace_xfs_fs_sync_fs(mp, __return_address);
 
@@ -744,7 +745,10 @@ xfs_fs_sync_fs(
 	if (!wait)
 		return 0;
 
-	xfs_log_force(mp, XFS_LOG_SYNC);
+	error = xfs_log_force(mp, XFS_LOG_SYNC);
+	if (error)
+		return error;
+
 	if (laptop_mode) {
 		/*
 		 * The disk must be active because we're syncing.