avfilter/vf_signature: Free inpads' names generically

Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavfilter/vf_signature.c

@@ -664,10 +664,8 @@ static av_cold int init(AVFilterContext *ctx)
 
         if (!pad.name)
             return AVERROR(ENOMEM);
-        if ((ret = ff_append_inpad(ctx, &pad)) < 0) {
-            av_freep(&pad.name);
+        if ((ret = ff_append_inpad_free_name(ctx, &pad)) < 0)
             return ret;
-        }
 
         sc = &(sic->streamcontexts[i]);
 
@@ -730,8 +728,6 @@ static av_cold void uninit(AVFilterContext *ctx)
         }
         av_freep(&sic->streamcontexts);
     }
-    for (unsigned i = 0; i < ctx->nb_inputs; i++)
-        av_freep(&ctx->input_pads[i].name);
 }
 
 static int config_output(AVFilterLink *outlink)