xfs: don't print warnings when xfs_log_force fails

There are only two reasons for xfs_log_force / xfs_log_force_lsn to fail:
one is an I/O error, for which xlog_bdstrat already logs a warning, and
the second is an already shutdown log due to a previous I/O errors.  In
the latter case we'll already have a previous indication for the actual
error, but the large stream of misleading warnings from xfs_log_force
will probably scroll it out of the message buffer.

Simply removing the warnings thus makes the XFS log reporting significantly
better.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

fs/xfs/xfs_log.c

@@ -3317,12 +3317,8 @@ xfs_log_force(
 	xfs_mount_t	*mp,
 	uint		flags)
 {
-	int	error;
-
 	trace_xfs_log_force(mp, 0, _RET_IP_);
-	error = _xfs_log_force(mp, flags, NULL);
-	if (error)
-		xfs_warn(mp, "%s: error %d returned.", __func__, error);
+	_xfs_log_force(mp, flags, NULL);
 }
 
 /*
@@ -3466,12 +3462,8 @@ xfs_log_force_lsn(
 	xfs_lsn_t	lsn,
 	uint		flags)
 {
-	int	error;
-
 	trace_xfs_log_force(mp, lsn, _RET_IP_);
-	error = _xfs_log_force_lsn(mp, lsn, flags, NULL);
-	if (error)
-		xfs_warn(mp, "%s: error %d returned.", __func__, error);
+	_xfs_log_force_lsn(mp, lsn, flags, NULL);
 }
 
 /*