dvdsubdec: Do not leak on failure path

CC: libav-stable@libav.org
Bug-Id: CID 1198262

libavcodec/dvdsubdec.c

@@ -503,6 +503,7 @@ static av_cold int dvdsub_init(AVCodecContext *avctx)
 {
     DVDSubContext *ctx = avctx->priv_data;
     char *data, *cur;
+    int ret = 0;
 
     if (!avctx->extradata || !avctx->extradata_size)
         return 0;
@@ -527,16 +528,18 @@ static av_cold int dvdsub_init(AVCodecContext *avctx)
         } else if (!strncmp("size:", cur, 5)) {
             int w, h;
             if (sscanf(cur + 5, "%dx%d", &w, &h) == 2) {
-               int ret = ff_set_dimensions(avctx, w, h);
+               ret = ff_set_dimensions(avctx, w, h);
                if (ret < 0)
-                   return ret;
+                   goto fail;
             }
         }
         cur += strcspn(cur, "\n\r");
         cur += strspn(cur, "\n\r");
     }
+
+fail:
     av_free(data);
-    return 0;
+    return ret;
 }
 
 AVCodec ff_dvdsub_decoder = {