xfs: check resblks before calling xfs_dir_canenter

Move the resblks test out of the xfs_dir_canenter,
and into the caller.

This makes a little more sense on the face of it;
xfs_dir_canenter immediately returns if resblks !=0;
and given some of the comments preceding the calls:

 * Check for ability to enter directory entry, if no space reserved.

even more so.

It also facilitates the next patch.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

diff --git a/fs/xfs/libxfs/xfs_dir2.h b/fs/xfs/libxfs/xfs_dir2.h
index c8e86b0..4dff261 100644
--- a/fs/xfs/libxfs/xfs_dir2.h
+++ b/fs/xfs/libxfs/xfs_dir2.h
@@ -136,7 +136,7 @@
 				xfs_fsblock_t *first,
 				struct xfs_bmap_free *flist, xfs_extlen_t tot);
 extern int xfs_dir_canenter(struct xfs_trans *tp, struct xfs_inode *dp,
-				struct xfs_name *name, uint resblks);
+				struct xfs_name *name);
 
 /*
  * Direct call from the bmap code, bypassing the generic directory layer.