SurfaceFlinger: mFbFence initialization

MobC00383030
b/12487813

SurfaceFlinger crash is observed while connecting
to Wi-Fi display.

Note: change 14e8b01a761180250671f3d6494532d8bd04fa8e
removed the initialization leading to the crash when
running through the HWC composition path.  Restore the
initialization to solve the problem.

Change-Id: I581defc7135ac512080c0da06a62b1dae7d218c4
Signed-off-by: mayank parshar <mayankp@broadcom.com>
Signed-off-by: Pierre Couillaud <pierre@broadcom.com>
diff --git a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp
index be5cf4a..e203903 100644
--- a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp
+++ b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp
@@ -458,6 +458,7 @@
     mCompositionType = COMPOSITION_UNKNOWN;
     mSinkBufferWidth = 0;
     mSinkBufferHeight = 0;
+    mFbFence = Fence::NO_FENCE;
     mOutputFence = Fence::NO_FENCE;
     mOutputProducerSlot = -1;
 }