Only destroy huffman if build succeeded.

The earlier code assumed that if jpeg_create_huffman_index
succeeded but jpeg_build_huffman_index failed that the
index would still need to be destroyed. This is not the
case. Only call jpeg_destroy_huffman_index if both
succeeded.

BUG=http://b.corp.google.com/issue?id=10263847

Review URL: https://codereview.chromium.org/22859042

git-svn-id: http://skia.googlecode.com/svn/trunk@10954 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/images/SkImageDecoder_libjpeg.cpp b/src/images/SkImageDecoder_libjpeg.cpp
index 788e352..2bd4818 100644
--- a/src/images/SkImageDecoder_libjpeg.cpp
+++ b/src/images/SkImageDecoder_libjpeg.cpp
@@ -143,9 +143,9 @@
         SkASSERT(fReadHeaderSucceeded);
         SkASSERT(!fHuffmanCreated);
         jpeg_create_huffman_index(&fCInfo, &fHuffmanIndex);
-        fHuffmanCreated = true;
         SkASSERT(1 == fCInfo.scale_num && 1 == fCInfo.scale_denom);
-        return jpeg_build_huffman_index(&fCInfo, &fHuffmanIndex);
+        fHuffmanCreated = jpeg_build_huffman_index(&fCInfo, &fHuffmanIndex);
+        return fHuffmanCreated;
     }
 
     /**