Close the AAC parse context, discovered by Netgem.

Originally committed as revision 17544 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/aac_parser.c

@@ -113,5 +113,5 @@ AVCodecParser aac_parser = {
     sizeof(AACAC3ParseContext),
     aac_parse_init,
     ff_aac_ac3_parse,
-    NULL,
+    ff_parse_close,
 };