hwc: Ensure pipe unset is called before wfd commit

In certain scenario, waiting for 2 vsync cycle may not be enough
for composition to trigger. In this case there is possibility of
wfd commit happening before pipe unset results in pipe not getting
cleaned up properly. Reusing pipe which is not cleaned up can lead
to crash or undetermined behaviour.

Change-Id: Ib5273e2d265ed19827204ab5316d1b5b1a27bd3d
2 files changed