avcodec/smvjpegdec: remove uninitialized ret

Signed-off-by: Limin Wang <lance.lmwang@gmail.com>

libavcodec/smvjpegdec.c

@@ -79,13 +79,12 @@ static av_cold int smvjpeg_decode_end(AVCodecContext *avctx)
 {
     SMVJpegDecodeContext *s = avctx->priv_data;
     MJpegDecodeContext *jpg = &s->jpg;
-    int ret;
 
     jpg->picture_ptr = NULL;
     av_frame_free(&s->picture[0]);
     av_frame_free(&s->picture[1]);
     avcodec_free_context(&s->avctx);
-    return ret;
+    return 0;
 }
 
 static av_cold int smvjpeg_decode_init(AVCodecContext *avctx)