xfs: fix small mismerge in xfs_vn_mknod

Identation got messed up when merging the current_umask changes with
the generic ACL support.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NFelix Blyakher <felixb@sgi.com>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>