Fix crash in TS muxer. Patch by Alex Antropoff.

Thanks.

Closes: #552

modules/mux/mpeg/pes.c

@@ -288,6 +288,7 @@ int E_( EStoPES )( sout_instance_t *p_sout, block_t **pp_pes, block_t *p_es,
         if( p_es )
         {
             p_es = block_Realloc( p_es, i_pes_header, p_es->i_buffer );
+            p_data = p_es->p_buffer+i_pes_header;
             /* reuse p_es for first frame */
             *pp_pes = p_pes = p_es;
             /* don't touch i_dts, i_pts, i_length as are already set :) */