Make the av_class member of PPContext a poiner to constant AVClass.

Patch by Diego 'Flameeyes' Pettenò flameeyes ¤ gmail ! com

Originally committed as revision 11445 to svn://svn.ffmpeg.org/ffmpeg/trunk

libpostproc/postprocess.c

@@ -982,7 +982,7 @@ static const char * context_to_name(void * ptr) {
     return "postproc";
 }
 
-static AVClass av_codec_context_class = { "Postproc", context_to_name, NULL };
+static const AVClass av_codec_context_class = { "Postproc", context_to_name, NULL };
 
 pp_context_t *pp_get_context(int width, int height, int cpuCaps){
         PPContext *c= av_malloc(sizeof(PPContext));

libpostproc/postprocess_internal.h

@@ -126,7 +126,7 @@ typedef struct PPContext{
         /**
          * info on struct for av_log
          */
-        AVClass *av_class;
+        const AVClass *av_class;
 
         uint8_t *tempBlocks; ///<used for the horizontal code