connector: remove lazy workqueue creation

Commit 1a5645bc (connector: create connector workqueue only while
needed once) implements lazy workqueue creation for connector
workqueue.  With cmwq now in place, lazy workqueue creation doesn't
make much sense while adding a lot of complexity.  Remove it and
allocate an ordered workqueue during initialization.

This also removes a call to flush_scheduled_work() which is deprecated
and scheduled to be removed.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>