fix format string warning

svn path=/trunk/KDE/kdenetwork/krfb/; revision=647260

libvncserver/main.c

@@ -74,7 +74,7 @@ rfbLog(const char *format, ...)
 
     time(&log_clock);
     strftime(buf, 255, "%d/%m/%Y %T ", localtime(&log_clock));
-    fprintf(stderr,buf);
+    fprintf(stderr,"%s", buf);
 
     vfprintf(stderr, format, args);
     fflush(stderr);