commit 
ad3fc7946b1829213bbdbb2b9ad0d124b31ae4a7 upstream.
After commit 
92082d40976ed0 ("btrfs: integrate page status update for
data read path into begin/end_page_read"), the 'nr' counter at
btrfs_do_readpage() is no longer used, we increment it but we never
read from it. So just remove it.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
        u64 cur_end;
        struct extent_map *em;
        int ret = 0;
-       int nr = 0;
        size_t pg_offset = 0;
        size_t iosize;
        size_t blocksize = inode->i_sb->s_blocksize;
                                         end_bio_extent_readpage, 0,
                                         this_bio_flag,
                                         force_bio_submit);
-               if (!ret) {
-                       nr++;
-               } else {
+               if (ret) {
                        unlock_extent(tree, cur, cur + iosize - 1);
                        end_page_read(page, false, cur, iosize);
                        goto out;