HWC2On1Adapter: Initialize variables and fix mutex

Initializes a few variables that had been missed before, and switches
the Adapter state mutex to be recursive, since it is held during the
call into HWC1 prepare, which can call back into the Adapter to perform
an invalidate.

Change-Id: Id300e8b23403f5339562fd860c2ce9d0f2b72f27