fix an off-by-one error in ADP file preload

verif/trace/verilog/nanosoc_axi_stream_io_8_txd_from_file.v

@@ -105,12 +105,13 @@ localparam BUFSIZE = (64 * 1024);
           $write("** %m : input file <%s> failed to open **\n", TXDFILENAME);
        else begin
          while (!$feof(fd)) begin
-           adpbuf[clen+25 + flen] <=  $fgetc(fd);
+           adpbuf[clen+25+1 + flen] =  $fgetc(fd);
            flen = flen +1;
            end
          $write("** %m : file closed after stream TX completed **\n");
          $fclose(fd);
        end
+   $write("** %m : input file length measured as: %d **\n", flen); 
        if (flen > 0) flen=flen-1; // correct for extra char count(???)
        // now output the entire adp buffer to the stream
        flen = flen + clen+25+1;