Fix capture stopping

When stopping the camera, the working thread should be stopped before sending
"stop" query to the emulator: we don't want "frame" queries to be floating around
while we're in the process of stopping the camera.

Change-Id: I16dc56ca1c2e304a07a074302001d2e27100f2ac

tools/emulator/system/camera/EmulatedFakeCameraDevice.cpp

@@ -90,7 +90,6 @@ status_t EmulatedFakeCameraDevice::startDevice()
 {
     LOGV("%s", __FUNCTION__);
 
-    Mutex::Autolock locker(&mObjectLock);
     if (!isConnected()) {
         LOGE("%s: Fake camera device is not connected.", __FUNCTION__);
         return EINVAL;