Fix memory leak in libgsm wrapper.

Patch by Martin Storsjö, martin at martin dot st



git-svn-id: file:///var/local/repositories/ffmpeg/trunk@15798 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavcodec/libgsm.c

@@ -89,6 +89,7 @@ static av_cold int libgsm_init(AVCodecContext *avctx) {
 }
 
 static av_cold int libgsm_close(AVCodecContext *avctx) {
+    av_freep(&avctx->coded_frame);
     gsm_destroy(avctx->priv_data);
     avctx->priv_data = NULL;
     return 0;