Update WelcomeScreen.cpp

Remove punctuation and capitalize abbreviation/code

Source/Project64/UserInterface/WelcomeScreen.cpp

@@ -119,8 +119,8 @@ int CALLBACK WelcomeScreen::SelectDirCallBack(HWND hwnd, DWORD uMsg, DWORD /*lp*
     switch (uMsg)
     {
     case BFFM_INITIALIZED:
-        // WParam is TRUE since you are passing a path.
-        // It would be FALSE if you were passing a pidl.
+        // WParam is TRUE since you are passing a path
+        // It would be FALSE if you were passing a PIDL
         if (lpData)
         {
             SendMessage(hwnd, BFFM_SETSELECTION, TRUE, lpData);