Use QFileInfo::exist(f) instead of QFileInfo(f).exists() if possible

Faster.

Change-Id: I91aa67462e11ff3258600d7f158de79942d0dc81
Reviewed-by: Marc Reilly <marc.reilly@gmail.com>
Reviewed-by: Christian Stenger <christian.stenger@digia.com>

src/plugins/cppeditor/fileandtokenactions_test.cpp

@@ -171,8 +171,7 @@ TestActionsTestCase::TestActionsTestCase(const Actions &tokenActions, const Acti
     // Process all files from the projects
     foreach (const QString filePath, filesToOpen) {
         // Skip e.g. "<configuration>"
-        const QFileInfo fileInfo(filePath);
-        if (!fileInfo.exists())
+        if (!QFileInfo::exists(filePath))
             continue;
 
         qDebug() << " --" << filePath;