VcsBase: Cleanup some Utils:: in cpp files

We are using namespace Utils in these files.

Change-Id: I0526f7e4fff2fe0d24d1e2b9fa087298d5331955
Reviewed-by: Orgad Shaneh <orgads@gmail.com>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>

src/plugins/vcsbase/submiteditorfile.cpp

@@ -52,8 +52,8 @@ SubmitEditorFile::SubmitEditorFile(VcsBaseSubmitEditor *editor) :
 }
 
 Core::IDocument::OpenResult SubmitEditorFile::open(QString *errorString,
-                                                   const Utils::FilePath &filePath,
-                                                   const Utils::FilePath &realFilePath)
+                                                   const FilePath &filePath,
+                                                   const FilePath &realFilePath)
 {
     if (filePath.isEmpty())
         return OpenResult::ReadError;