macosx: set 'freetype-font' to the postscript name instead of the family name

This fixes the freetype ATS lookup for some Asian fonts such as Hiragino Micho ProN with multiple weights.

modules/gui/macosx/simple_prefs.m

@@ -1227,7 +1227,7 @@ static inline void save_module_list( intf_thread_t * p_intf, id object, const ch
 - (void)changeFont:(id)sender
 {
     NSFont * font = [sender convertFont:[[NSFontManager sharedFontManager] selectedFont]];
-    [o_osd_font_fld setStringValue:[font familyName]];
+    [o_osd_font_fld setStringValue:[font fontName]];
     [self osdSettingChanged:self];
 }