Camera: Fix race condition in snapshot.

Change-Id: I917994f3bb4663eb33ffa2c76754947f70f3cd5e
Bug: 13620972
diff --git a/camera/QCameraHWI_Still.cpp b/camera/QCameraHWI_Still.cpp
index 83bb783..34d8765 100755
--- a/camera/QCameraHWI_Still.cpp
+++ b/camera/QCameraHWI_Still.cpp
@@ -2082,11 +2082,13 @@
             goto end;
         }
 
+        mStopCallbackLock.unlock();
         if(!mHalCamCtrl->mShutterSoundPlayed) {
             notifyShutter(&crop, true);
         }
         notifyShutter(&crop, false);
         mHalCamCtrl->mShutterSoundPlayed = false;
+        mStopCallbackLock.lock();
 
         if(mHalCamCtrl->mHdrMode == HDR_MODE) {
             if ((hdrRawCount % 3) != 2) {