Close the va_list

Add missing va_end() to debug code.
Found by cppcheck static analysis.
Tagged as RedrawMgr-0_09-1 since our va_end is an empty macro.

c/main

@@ -111,6 +111,7 @@ static void debug_output(char *tag,char *fmt,...)
 
    va_start(list,fmt);
    vsprintf(buf,fmt,list);
+   va_end(list);
    debug_string(buf,tag);
 
 }