Fix unsafe usage of the logging functions.


git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@4905 3789f03b-4d11-0410-bbf8-ca57d06f2519
diff --git a/common/rfb/SConnection.cxx b/common/rfb/SConnection.cxx
index 941d30a..ee57336 100644
--- a/common/rfb/SConnection.cxx
+++ b/common/rfb/SConnection.cxx
@@ -239,7 +239,7 @@
 
 void SConnection::throwConnFailedException(const char* msg)
 {
-  vlog.info(msg);
+  vlog.info("%s", msg);
   if (state_ == RFBSTATE_PROTOCOL_VERSION) {
     if (cp.majorVersion == 3 && cp.minorVersion == 3) {
       os->writeU32(0);