xfs: move xattr scrub buffer allocation to top level function

Move the xchk_setup_xattr_buf call from xchk_xattr_block to xchk_xattr,
since we only need to set up the leaf block bitmaps once.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

fs/xfs/scrub/attr.c

@@ -346,18 +346,10 @@ xchk_xattr_block(
 	unsigned int			usedbytes = 0;
 	unsigned int			hdrsize;
 	int				i;
-	int				error;
 
 	if (*last_checked == blk->blkno)
 		return 0;
 
-	/* Allocate memory for block usage checking. */
-	error = xchk_setup_xattr_buf(ds->sc, 0);
-	if (error == -ENOMEM)
-		return -EDEADLOCK;
-	if (error)
-		return error;
-
 	*last_checked = blk->blkno;
 	bitmap_zero(ab->usedmap, mp->m_attr_geo->blksize);
 
@@ -507,6 +499,13 @@ xchk_xattr(
 	if (!xfs_inode_hasattr(sc->ip))
 		return -ENOENT;
 
+	/* Allocate memory for xattr checking. */
+	error = xchk_setup_xattr_buf(sc, 0);
+	if (error == -ENOMEM)
+		return -EDEADLOCK;
+	if (error)
+		return error;
+
 	memset(&sx, 0, sizeof(sx));
 	/* Check attribute tree structure */
 	error = xchk_da_btree(sc, XFS_ATTR_FORK, xchk_xattr_rec,