loplugin:override: No more need to request dtor be marked 'virtual'

...rather than 'override', cf. <https://gerrit.libreoffice.org/#/c/26347/>
"loplugin:override: No more need for the "MSVC dtor override" workaround".

Change-Id: Ib528938ed4be248117bb7114f34d4e9421bc3275

compilerplugins/clang/override.cxx

@@ -67,7 +67,7 @@ bool Override::VisitCXXMethodDecl(CXXMethodDecl const * decl) {
             report(
                 DiagnosticsEngine::Warning,
                 ("overriding destructor declaration not explicitly marked"
-                 " 'virtual'"),
+                 " 'override'"),
                 decl->getLocation())
                 << decl->getSourceRange();
         }