btrfs: convert try_release_extent_state() to take a folio

The old page API is being gradually replaced and converted to use folio
to improve code readability and avoid repeated conversion between page
and folio. Moreover, use folio_pos() instead of page_offset(),
which is more consistent with folio usage.

Signed-off-by: Li Zetao <[e-mail]>
Reviewed-by: David Sterba <[e-mail]>
Signed-off-by: David Sterba <[e-mail]>

fs/btrfs/extent_io.c

···
  * to drop the page.
  */
 static bool try_release_extent_state(struct extent_io_tree *tree,
-				    struct page *page, gfp_t mask)
+				    struct folio *folio, gfp_t mask)
 {
-	u64 start = page_offset(page);
+	u64 start = folio_pos(folio);
 	u64 end = start + PAGE_SIZE - 1;
 	bool ret;
 
···
 			cond_resched();
 		}
 	}
-	return try_release_extent_state(io_tree, page, mask);
+	return try_release_extent_state(io_tree, folio, mask);
 }
 
 static void __free_extent_buffer(struct extent_buffer *eb)