MT#62181 XmlRpcClient: add setFault()

Make it more explicit that this is meant to set the flag instead of
doing a comparison with a typo.

Change-Id: I31a1a7f35b9072f157105f6c2acdd2caf9bea09a
Warned-by: Coverity

apps/xmlrpc2di/xmlrpc++/src/XmlRpcClient.cpp

@@ -528,7 +528,7 @@ XmlRpcClient::parseResponse(XmlRpcValue& result)
   // Expect either <params><param>... or <fault>...
   if ((XmlRpcUtil::nextTagIs(PARAMS_TAG,_response,&offset) &&
        XmlRpcUtil::nextTagIs(PARAM_TAG,_response,&offset)) ||
-      (XmlRpcUtil::nextTagIs(FAULT_TAG,_response,&offset) && (_isFault = true)))
+      (XmlRpcUtil::nextTagIs(FAULT_TAG,_response,&offset) && setFault()))
   {
     if ( ! result.fromXml(_response, &offset)) {
       XmlRpcUtil::error("Error in XmlRpcClient::parseResponse: Invalid response value. Response:\n%s", _response.c_str());

apps/xmlrpc2di/xmlrpc++/src/XmlRpcClient.h

@@ -141,6 +141,9 @@ namespace XmlRpc {
     // Event dispatcher
     XmlRpcDispatch _disp;
 
+  private:
+    //! Sets the fault flag and returns true.
+    bool setFault() { _isFault = true; return true; }
   };	// class XmlRpcClient
 
 }	// namespace XmlRpc