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/compilationdatabaseprojectmanager/compilationdatabaseutils.h

@@ -44,7 +44,7 @@ namespace Internal {
 class DbEntry {
 public:
     QStringList flags;
-    Utils::FileName fileName;
+    Utils::FilePath fileName;
     QString workingDir;
 };