btrfs: remove unused function prototypes

I wrote the following coccinelle script to find function declarations
that didn't have the corresponding code for them

@funcproto@
identifier func;
type T;
position p0;
@@

T func@p0(...);

@funccode@
identifier funcproto.func;
position p1;
@@

func@p1(...) { ... }

@script:python depends on !funccode@
p0 << funcproto.p0;
@@
print("Proto with no function at %s:%s" % (p0[0].file, p0[0].line))

and ran it against btrfs, which identified the 4 function prototypes
I've removed in this patch.
Signed-off-by: NJosef Bacik <josef@toxicpanda.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/ctree.h

@@ -739,7 +739,6 @@ int btrfs_insert_orphan_item(struct btrfs_trans_handle *trans,
 			     struct btrfs_root *root, u64 offset);
 int btrfs_del_orphan_item(struct btrfs_trans_handle *trans,
 			  struct btrfs_root *root, u64 offset);
-int btrfs_find_orphan_item(struct btrfs_root *root, u64 offset);
 
 /* file-item.c */
 int btrfs_del_csums(struct btrfs_trans_handle *trans,
@@ -924,8 +923,6 @@ int __pure btrfs_is_empty_uuid(u8 *uuid);
 int btrfs_defrag_file(struct inode *inode, struct file_ra_state *ra,
 		      struct btrfs_ioctl_defrag_range_args *range,
 		      u64 newer_than, unsigned long max_to_defrag);
-void btrfs_get_block_group_info(struct list_head *groups_list,
-				struct btrfs_ioctl_space_info *space);
 void btrfs_update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
 			       struct btrfs_ioctl_balance_args *bargs);
 

fs/btrfs/disk-io.h

@@ -116,8 +116,6 @@ int btrfs_read_extent_buffer(struct extent_buffer *buf, u64 parent_transid,
 bool btrfs_wq_submit_bio(struct inode *inode, struct bio *bio, int mirror_num,
 			 u64 dio_file_offset,
 			 extent_submit_bio_start_t *submit_bio_start);
-blk_status_t btrfs_submit_bio_done(void *private_data, struct bio *bio,
-			  int mirror_num);
 int btrfs_alloc_log_tree_node(struct btrfs_trans_handle *trans,
 			      struct btrfs_root *root);
 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
@@ -130,8 +128,6 @@ void btrfs_cleanup_one_transaction(struct btrfs_transaction *trans,
 				  struct btrfs_fs_info *fs_info);
 struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 				     u64 objectid);
-int btree_lock_page_hook(struct page *page, void *data,
-				void (*flush_fn)(void *));
 int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags);
 int btrfs_get_free_objectid(struct btrfs_root *root, u64 *objectid);
 int btrfs_init_root_free_objectid(struct btrfs_root *root);