xfs: fix unreferenced var error in xfs_buf.c

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index 596bb2c..d917146 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -657,8 +657,6 @@
 	xfs_off_t		ioff,
 	size_t			isize)
 {
-	struct backing_dev_info *bdi;
-
 	if (bdi_read_congested(target->bt_bdi))
 		return;