Otherwise, freetype_get_glyph_outline() fails at FT_Load_Glyph due to
combination of base_font's ft_face and child font's glyph index.

Fixes a regression introduced by 044315c0.
Signed-off-by: Akihiro Sagawa <sagawa.aki@gmail.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>