ctdb-locking: Remove multiple lock requests per lock context (part 1)

ctdb-locking: Remove multiple lock requests per lock context (part 1)

This was a bad idea and caused out of order scheduling of lock requests.

The logic to append lock requests to existing lock context is already
commented.  Remove the commented code and there is no need to check if
lock_ctx is NULL, since we are always creating a new one.

Signed-off-by: Amitay Isaacs <amitay@gmail.com>
Reviewed-by: Volker Lendecke <vl@samba.org>