windeployqt: Use default constructor of QString and then append

Addressing a comment from the review of QTBUG-98434.

Instead of assigning an initial value to the QString, create an empty
QString first and then append to the QString.

Task-number: QTBUG-103100
Change-Id: I8f2569ac2a2203e6459bbc7df789c9ef34f598d0
Reviewed-by: Marc Mutz <marc.mutz@qt.io>

src/tools/windeployqt/main.cpp

@@ -669,7 +669,8 @@ static inline QString helpText(const QCommandLineParser &p)
     const qsizetype argumentsStart = result.lastIndexOf("\nArguments:"_L1);
     if (moduleStart >= argumentsStart)
         return result;
-    QString moduleHelp =
+    QString moduleHelp;
+    moduleHelp +=
         "\n\nQt libraries can be added by passing their name (-xml) or removed by passing\n"
         "the name prepended by --no- (--no-xml). Available libraries:\n"_L1;
     moduleHelp += lineBreak(QString::fromLatin1(formatQtModules(0xFFFFFFFFFFFFFFFFull, true)));