Do not multiply return value of CTFontGetDescent with -1
Do not multiply return value of CTFontGetDescent with -1

The return value of CTFontGetDescent is already positive, as opposed
to the ats_metrics.descent value used before.  This is a regression
introduced by the previous patch "porting" the backend to CoreText, which
also broke support for Tiger and earlier -- we will fix that soonish.

OpenInkpot-archive/iplinux-pango1.0,kari-lentz/alpha-pango,Distrotech/pango,Distrotech/pango,Distrotech/pango,kari-lentz/alpha-pango,danny-ku/pango,kari-lentz/alpha-pango,OpenInkpot-archive/iplinux-pango1.0,danny-ku/pango,kari-lentz/alpha-pango,danny-ku/pango,OpenInkpot-archive/iplinux-pango1.0