Fix a typo on masking face id

Most of functionality should be moved to FcFreeTypeQueryAll()
for varfonts now though, if doing the same to FcFreeTypeQuery()
returns Null pattern because of inappropriate masking.

This might be not that big deal for varfonts support. but

Fixes https://gitlab.freedesktop.org/fontconfig/fontconfig/issues/162

Reported by Kevin Scott
1 file changed