btrfs: sink get_extent parameter to extent_write_locked_range

There's only one caller.
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/extent_io.c

@@ -4077,8 +4077,7 @@ int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
 }
 
 int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
-			      u64 start, u64 end, get_extent_t *get_extent,
-			      int mode)
+			      u64 start, u64 end, int mode)
 {
 	int ret = 0;
 	struct address_space *mapping = inode->i_mapping;
@@ -4089,7 +4088,7 @@ int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
 	struct extent_page_data epd = {
 		.bio = NULL,
 		.tree = tree,
-		.get_extent = get_extent,
+		.get_extent = btrfs_get_extent,
 		.extent_locked = 1,
 		.sync_io = mode == WB_SYNC_ALL,
 	};

fs/btrfs/extent_io.h

@@ -407,8 +407,7 @@ int extent_write_full_page(struct extent_io_tree *tree, struct page *page,
 			  get_extent_t *get_extent,
 			  struct writeback_control *wbc);
 int extent_write_locked_range(struct extent_io_tree *tree, struct inode *inode,
-			      u64 start, u64 end, get_extent_t *get_extent,
-			      int mode);
+			      u64 start, u64 end, int mode);
 int extent_writepages(struct extent_io_tree *tree,
 		      struct address_space *mapping,
 		      struct writeback_control *wbc);

fs/btrfs/inode.c

@@ -769,7 +769,6 @@ static noinline void submit_compressed_extents(struct inode *inode,
 						  inode, async_extent->start,
 						  async_extent->start +
 						  async_extent->ram_size - 1,
-						  btrfs_get_extent,
 						  WB_SYNC_ALL);
 			else if (ret)
 				unlock_page(async_cow->locked_page);