xfs: remove the XBF_STALE check from xfs_buf_rele_cached

xfs_buf_stale already set b_lru_ref to 0, and thus prevents the buffer
from moving to the LRU.  Remove the duplicate check.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

fs/xfs/xfs_buf.c

@@ -99,12 +99,6 @@ xfs_buf_stale(
 	 */
 	bp->b_flags &= ~_XBF_DELWRI_Q;
 
-	/*
-	 * Once the buffer is marked stale and unlocked, a subsequent lookup
-	 * could reset b_flags. There is no guarantee that the buffer is
-	 * unaccounted (released to LRU) before that occurs. Drop in-flight
-	 * status now to preserve accounting consistency.
-	 */
 	spin_lock(&bp->b_lock);
 	atomic_set(&bp->b_lru_ref, 0);
 	if (!(bp->b_state & XFS_BSTATE_DISPOSE) &&
@@ -1033,7 +1027,7 @@ xfs_buf_rele_cached(
 	}
 
 	/* we are asked to drop the last reference */
-	if (!(bp->b_flags & XBF_STALE) && atomic_read(&bp->b_lru_ref)) {
+	if (atomic_read(&bp->b_lru_ref)) {
 		/*
 		 * If the buffer is added to the LRU, keep the reference to the
 		 * buffer for the LRU and clear the (now stale) dispose list