avformat/utils: remove unused variable

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/utils.c

@@ -347,7 +347,6 @@ int av_probe_input_buffer2(AVIOContext *pb, AVInputFormat **fmt,
 
     for(probe_size= PROBE_BUF_MIN; probe_size<=max_probe_size && !*fmt;
         probe_size = FFMIN(probe_size<<1, FFMAX(max_probe_size, probe_size+1))) {
-        void *buftmp;
 
         if (probe_size < offset) {
             continue;