msm: ipa3: Fix to destory workqueue only if created

Freepage workqueue created only for few pipes, while handling error
scenarios freeing it for all pipes. So adding check to free work queue
only if created.

Change-Id: I8bf097c02f6acd0a4a22b3d4bc5b66f46884fc1e
Signed-off-by: Ashok Vuyyuru <quic_avuyyuru@quicinc.com>