Fix a memory leak in cmykjpeg GM.

Review URL: https://codereview.appspot.com/6448089

git-svn-id: http://skia.googlecode.com/svn/trunk@4861 2bbb7eff-a529-9590-31e7-b0007b416f81

gm/cmykjpeg.cpp

@@ -37,6 +37,7 @@ public:
             codec->setDitherImage(dither);
             codec->decode(&stream, &fBitmap, prefConfig,
                           SkImageDecoder::kDecodePixels_Mode);
+            SkDELETE(codec);
         }
     }