btrfs: remove the second argument of k[un]map_atomic()

Signed-off-by: Cong Wang <amwang@redhat.com>

fs/btrfs/file-item.c

@@ -447,13 +447,13 @@ int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
 			sums->bytenr = ordered->start;
 		}
 
-		data = kmap_atomic(bvec->bv_page, KM_USER0);
+		data = kmap_atomic(bvec->bv_page);
 		sector_sum->sum = ~(u32)0;
 		sector_sum->sum = btrfs_csum_data(root,
 						  data + bvec->bv_offset,
 						  sector_sum->sum,
 						  bvec->bv_len);
-		kunmap_atomic(data, KM_USER0);
+		kunmap_atomic(data);
 		btrfs_csum_final(sector_sum->sum,
 				 (char *)&sector_sum->sum);
 		sector_sum->bytenr = disk_bytenr;