xfs: cleanup log unmount handling

Kill the current xfs_log_unmount wrapper and opencode the two function
calls in the only caller.  Rename the current xfs_log_unmount_dealloc to
xfs_log_unmount as it undoes xfs_log_mount and the new name makes that
more clear.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
diff --git a/fs/xfs/xfs_log.h b/fs/xfs/xfs_log.h
index 8a3e84e..d0c9baa 100644
--- a/fs/xfs/xfs_log.h
+++ b/fs/xfs/xfs_log.h
@@ -170,9 +170,8 @@
 			int		 nentries,
 			xfs_log_ticket_t ticket,
 			xfs_lsn_t	 *start_lsn);
-int	  xfs_log_unmount(struct xfs_mount *mp);
 int	  xfs_log_unmount_write(struct xfs_mount *mp);
-void      xfs_log_unmount_dealloc(struct xfs_mount *mp);
+void      xfs_log_unmount(struct xfs_mount *mp);
 int	  xfs_log_force_umount(struct xfs_mount *mp, int logerror);
 int	  xfs_log_need_covered(struct xfs_mount *mp);