Remove accidental global variable from the font sample

This variable was never used and appears to have been created
accidentally, so just remove it and avoid variable shadowing warnings
from MSVS 2015 when building the sample.

samples/font/font.cpp

@@ -476,7 +476,7 @@ protected:
 
     private:
         wxArrayString m_facenames;
-} fontEnumerator;
+};
 
 bool MyFrame::DoEnumerateFamilies(bool fixedWidthOnly,
                                   wxFontEncoding encoding,