Reset lock complete variable after lock
adfae584 changed the greeter to notify out of band that the lock has been successfully lifted.
s_lockProcessRequestedExit represents the state between unlock occurring and the greeter exiting. This was not reset when we next showed the lockscreen.
A symptom amongst others is that the grace locker would be broken if used after a successful lock.
Note the change is in ksldapp meaning to test requires restarting kwin_wayland / ksmserver (x11).