Utils: Rename FileName to FilePath

More in line with QFileInfo terminonlogy which appears to be
best-of-breed within Qt.

Change-Id: I1d051ff1c8363ebd4ee56376451df45216c4c9ab
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/debugger/debuggerdialogs.cpp

@@ -172,7 +172,7 @@ QString StartApplicationParameters::displayName() const
 {
     const int maxLength = 60;
 
-    QString name = FileName::fromString(runnable.executable).fileName()
+    QString name = FilePath::fromString(runnable.executable).fileName()
             + ' ' + runnable.commandLineArguments;
     if (name.size() > 60) {
         int index = name.lastIndexOf(' ', maxLength);