btrfs: open code trivial helper btrfs_page_exists_in_range

The called function name is self explanatory.

Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 8f425c6..8cac400 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -2482,7 +2482,8 @@ static int btrfs_punch_hole_lock_range(struct inode *inode,
 		if ((!ordered ||
 		    (ordered->file_offset + ordered->len <= lockstart ||
 		     ordered->file_offset > lockend)) &&
-		     !btrfs_page_exists_in_range(inode, lockstart, lockend)) {
+		     !filemap_range_has_page(inode->i_mapping,
+					     lockstart, lockend)) {
 			if (ordered)
 				btrfs_put_ordered_extent(ordered);
 			break;