Fix the initialize of PreviewImageData to its default values.

Bug: 26762780, 26837999
Change-Id: Ifc268beb84903576b8c82681fddf2f51ffc4a2ec
diff --git a/media/jni/android_media_Utils.cpp b/media/jni/android_media_Utils.cpp
index 5108eb5..c08a5e3 100644
--- a/media/jni/android_media_Utils.cpp
+++ b/media/jni/android_media_Utils.cpp
@@ -81,7 +81,8 @@
 
 bool GetExifFromRawImage(
         FileStream* stream, const String8& filename, piex::PreviewImageData& image_data) {
-    memset(&image_data, 0, sizeof(image_data));
+    // Reset the PreviewImageData to its default.
+    image_data = piex::PreviewImageData();
 
     if (!stream->exists()) {
         // File is not exists.