filelock: reorganize locks_delete_block and __locks_insert_block

filelock: reorganize locks_delete_block and __locks_insert_block

Rename the old __locks_delete_block to __locks_unlink_lock. Rename
change old locks_delete_block function to __locks_delete_block and
have it take a file_lock_core. Make locks_delete_block a simple wrapper
around __locks_delete_block.

Also, change __locks_insert_block to take struct file_lock_core, and
fix up its callers.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20240131-flsplit-v3-28-c6129007ee8d@kernel.org
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>