[RAMEN9610-14499][common][9610] wlbt: fix completion and use completion_done API

[RAMEN9610-14499][common][9610] wlbt: fix completion and use completion_done API

When we get rapid requests for SABLE generation, to serialise while processing current request,
we ignore requests other than "fw_panic" in wlbtd and send a msg "ignoring" back to kernel.
We must complete in this case as well.

We must complete one completion upon message from wlbtdi, which has
waiter(s). completion_done() API does the check without modifying
the completion in anyway and returns false if there are waiters and
true otherwise

SCSC-Bug-Id: ssb-51156
previous patch :
-Change-Id: Ieabcd8377a3040bdcfe51e4310eb55d84c693446
-Signed-off-by: Purnendu Kapadia <p.kapadia@samsung.com>

Change-Id: Id6ff01e96b2e1e3de7f940c9e2ef1a75211ae5dd
Signed-off-by: Youngsoo <youngss.kim@samsung.com>