avcodec/dirac: Fix memleak of dsh on error

Fixes CID1351360
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/dirac.c

@@ -349,8 +349,10 @@ int av_dirac_parse_sequence_header(AVDiracSeqHeader **pdsh,
     else if (dsh->version.major > 2 && log_ctx)
         av_log(log_ctx, AV_LOG_WARNING, "Stream may have unhandled features\n");
 
-    if (video_format > 20U)
-        return AVERROR_INVALIDDATA;
+    if (video_format > 20U) {
+        ret = AVERROR_INVALIDDATA;
+        goto fail;
+    }
 
     /* Fill in defaults for the source parameters. */
     dsh->width              = dirac_source_parameters_defaults[video_format].width;