btrfs: subpage: remove the unused error bitmap dumping

Since commit 2b2553f12355 ("btrfs: stop setting PageError in the data I/O
path") btrfs no longer utilizes subpage error bitmaps anymore, but the
commit forgot to remove the error bitmap in btrfs_subpage_dump_bitmap(),
resulting in possible meaningless result for the error bitmap.

Fix it by just removing the error bitmap dumping.

Signed-off-by: Qu Wenruo <[e-mail]>
Reviewed-by: David Sterba <[e-mail]>
Signed-off-by: David Sterba <[e-mail]>

fs/btrfs/subpage.c

···
 	struct btrfs_subpage_info *subpage_info = fs_info->subpage_info;
 	struct btrfs_subpage *subpage;
 	unsigned long uptodate_bitmap;
-	unsigned long error_bitmap;
 	unsigned long dirty_bitmap;
 	unsigned long writeback_bitmap;
 	unsigned long ordered_bitmap;
···
 
 	dump_page(folio_page(folio, 0), "btrfs subpage dump");
 	btrfs_warn(fs_info,
-"start=%llu len=%u page=%llu, bitmaps uptodate=%*pbl error=%*pbl dirty=%*pbl writeback=%*pbl ordered=%*pbl checked=%*pbl",
+"start=%llu len=%u page=%llu, bitmaps uptodate=%*pbl dirty=%*pbl writeback=%*pbl ordered=%*pbl checked=%*pbl",
 		    start, len, folio_pos(folio),
 		    subpage_info->bitmap_nr_bits, &uptodate_bitmap,
-		    subpage_info->bitmap_nr_bits, &error_bitmap,
 		    subpage_info->bitmap_nr_bits, &dirty_bitmap,
 		    subpage_info->bitmap_nr_bits, &writeback_bitmap,
 		    subpage_info->bitmap_nr_bits, &ordered_bitmap,