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/clangtools/clangtool.h

@@ -31,7 +31,7 @@
 #include <cpptools/projectinfo.h>
 
 namespace Debugger { class DetailedErrorView; }
-namespace Utils { class FileName; }
+namespace Utils { class FilePath; }
 
 namespace ClangTools {
 namespace Internal {
@@ -50,7 +50,7 @@ public:
     virtual void startTool(bool askUserForFileSelection) = 0;
 
     virtual QList<Diagnostic> read(const QString &filePath,
-                                   const Utils::FileName &projectRootDir,
+                                   const Utils::FilePath &projectRootDir,
                                    const QString &logFilePath,
                                    QString *errorMessage) const = 0;