xfs: remove stale parameter from ->iop_unpin method

The staleness of a object being unpinned can be directly derived
from the object itself - there is no need to extract it from the
object then pass it as a parameter into IOP_UNPIN().

This means we can kill the XFS_LID_BUF_STALE flag - it is set,
checked and cleared in the same places XFS_BLI_STALE flag in the
xfs_buf_log_item so it is now redundant and hence safe to remove.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

fs/xfs/xfs_trans.c

@@ -1451,6 +1451,6 @@ xfs_trans_chunk_committed(
 		 * flags, if anyone else stales the buffer we do not
 		 * want to pay any attention to it.
 		 */
-		IOP_UNPIN(lip, lidp->lid_flags & XFS_LID_BUF_STALE);
+		IOP_UNPIN(lip);
 	}
 }