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.
(cherry picked from commit 26303bdd)

modules/gui/macosx/simple_prefs.m

@@ -1221,7 +1221,7 @@ 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];
 }