Change warning error string management => do like NI examples to avoid bad...

Change warning error string management => do like NI examples to avoid bad memory allocation (TANGODEVIC-787)

src/CounterBasedOperation.cpp

@@ -295,11 +295,9 @@ throw (ni660Xsl::DAQException)
 // ============================================================================
 std::string CounterBasedOperation::get_string_error(void)
 {
-	long size = DAQmxGetExtendedErrorInfo(NULL,0);
-	char* string_err = new char[size];
-	DAQmxGetExtendedErrorInfo(string_err, size);
-	std::string s = string_err;
-	delete	[] string_err;
+  char errBuff[2048] = {'\0'};
+  DAQmxGetExtendedErrorInfo(errBuff,2048);
+	std::string s = errBuff;
 	return s;
 }
 // ============================================================================