gfs2: Fixes to "Implement iomap for block_map" (2)

It turns out that commit 3229c18c0d6b2 'Fixes to "Implement iomap for
block_map"' introduced another bug in gfs2_iomap_begin that can cause
gfs2_block_map to set bh->b_size of an actual buffer to 0.  This can
lead to arbitrary incorrect behavior including crashes or disk
corruption.  Revert the incorrect part of that commit.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 86d6a44..51f940e 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -807,9 +807,6 @@
 			iomap->length = hole_size(inode, lblock, &mp);
 		else
 			iomap->length = size - pos;
-	} else {
-		if (height <= ip->i_height)
-			iomap->length = hole_size(inode, lblock, &mp);
 	}
 	goto out_release;
 }