gfs2: use iomap_bmap instead of generic_block_bmap

No need to indirect through get_blocks and buffer_heads when we can just use
the iomap version.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

fs/gfs2/aops.c

@@ -697,7 +697,7 @@ static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
 		return 0;
 
 	if (!gfs2_is_stuffed(ip))
-		dblock = generic_block_bmap(mapping, lblock, gfs2_block_map);
+		dblock = iomap_bmap(mapping, lblock, &gfs2_iomap_ops);
 
 	gfs2_glock_dq_uninit(&i_gh);