avmedia: Drop PlayerListener_BASE typedef

It's only used once, in the next line.

Change-Id: I9793f8dd515e851571a45724e1c253232aa32e25
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/199799
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>
Tested-by: Jenkins

include/avmedia/mediawindow.hxx

@@ -54,9 +54,8 @@ namespace avmedia
 
     namespace priv { class MediaWindowImpl; }
 
-    typedef comphelper::WeakComponentImplHelper<css::media::XPlayerListener> PlayerListener_BASE;
-
-    class AVMEDIA_DLLPUBLIC PlayerListener final : public PlayerListener_BASE
+    class AVMEDIA_DLLPUBLIC PlayerListener final
+        : public comphelper::WeakComponentImplHelper<css::media::XPlayerListener>
     {
     private:
         css::uno::Reference<css::media::XPlayerNotifier> m_xNotifier;