btrfs: remove unused key type set/get helpers

The switch to open coded set/get has happend long time ago in
962a298f ("btrfs: kill the key type accessor helpers"), remove the
stray helpers.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/ctree.h

@@ -2069,16 +2069,6 @@ static inline void btrfs_dir_item_key_to_cpu(const struct extent_buffer *eb,
 	btrfs_disk_key_to_cpu(key, &disk_key);
 }
 
-static inline u8 btrfs_key_type(const struct btrfs_key *key)
-{
-	return key->type;
-}
-
-static inline void btrfs_set_key_type(struct btrfs_key *key, u8 val)
-{
-	key->type = val;
-}
-
 /* struct btrfs_header */
 BTRFS_SETGET_HEADER_FUNCS(header_bytenr, struct btrfs_header, bytenr, 64);
 BTRFS_SETGET_HEADER_FUNCS(header_generation, struct btrfs_header,