avfilter/buffersrc: Remove unused variables

Unused since f09ae730.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavfilter/buffersrc.c

@@ -435,8 +435,6 @@ static int config_props(AVFilterLink *link)
 static int request_frame(AVFilterLink *link)
 {
     BufferSourceContext *c = link->src->priv;
-    AVFrame *frame;
-    int ret;
 
     if (c->eof)
         return AVERROR_EOF;