btrfs: Remove redundant forward declarations

Some static functions are needlessly forward declared. Let's remove those
declarations since they add no value.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/extent-tree.c

@@ -61,9 +61,6 @@ enum {
 	CHUNK_ALLOC_FORCE = 2,
 };
 
-static int update_block_group(struct btrfs_trans_handle *trans,
-			      struct btrfs_fs_info *fs_info, u64 bytenr,
-			      u64 num_bytes, int alloc);
 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
 			       struct btrfs_fs_info *fs_info,
 				struct btrfs_delayed_ref_node *node, u64 parent,
@@ -91,17 +88,8 @@ static int find_next_key(struct btrfs_path *path, int level,
 static void dump_space_info(struct btrfs_fs_info *fs_info,
 			    struct btrfs_space_info *info, u64 bytes,
 			    int dump_block_groups);
-static int btrfs_add_reserved_bytes(struct btrfs_block_group_cache *cache,
-				    u64 ram_bytes, u64 num_bytes, int delalloc);
-static int btrfs_free_reserved_bytes(struct btrfs_block_group_cache *cache,
-				     u64 num_bytes, int delalloc);
 static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv,
 			       u64 num_bytes);
-static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info,
-				    struct btrfs_space_info *space_info,
-				    u64 orig_bytes,
-				    enum btrfs_reserve_flush_enum flush,
-				    bool system_chunk);
 static void space_info_add_new_bytes(struct btrfs_fs_info *fs_info,
 				     struct btrfs_space_info *space_info,
 				     u64 num_bytes);