Corrected flaws found by George Danchev with cpp

xorriso/text_io.c

@@ -106,7 +106,7 @@ get_single:;
    l= strlen(cpt);
    if(l >= linesize - base_length - 1) {
      strncpy(linept, cpt, linesize - 1);
-     line[sizeof(line)-1]= 0;
+     line[linesize - 1]= 0;
      sprintf(xorriso->info_text,"Input line too long !");
      Xorriso_msgs_submit(xorriso, 0, xorriso->info_text, 0, "SORRY", 0);
      goto new_empty;