pnfs/blocklayout: pnfs_block_dev_map uses bytes, not sectors

Fixup the field types to match their use.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trondmy@gmail.com>

fs/nfs/blocklayout/blocklayout.h

@@ -92,10 +92,9 @@ struct pnfs_block_volume {
 };
 
 struct pnfs_block_dev_map {
-	sector_t			start;
-	sector_t			len;
-
-	sector_t			disk_offset;
+	u64			start;
+	u64			len;
+	u64			disk_offset;
 	struct block_device		*bdev;
 };