ensure that we call onUnlock only when we onLock succeeded

src/images/SkImageRef_ashmem.cpp

-
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
+
 #include "SkImageRef_ashmem.h"
 #include "SkImageDecoder.h"
 #include "SkFlattenableBuffers.h"
 #include "SkThread.h"
 
 #include "android/ashmem.h"
 
 #include <sys/mman.h>
 #include <unistd.h>
 
@@ skipping 206 matching lines @@
     fRec.fFD = -1;
     fRec.fAddr = NULL;
     fRec.fSize = 0;
     fRec.fPinned = false;
     fCT = NULL;
 
     SkString uri;
     buffer.readString(&uri);
     this->setURI(uri);
 }