Fix for fontconfig 2.9 behavior change

Fix for fontconfig 2.9 behavior change

Start from 2.9, fontconfig will reset the result to FcResultNoMatch at
the beginning of FcFontSort().

According to
http://lists.freedesktop.org/archives/fontconfig/2012-March/003857.html
the result value of FcFontSort() can be ignored, checking the nfont
value of the fontset returned is sufficient.

The fix works for pre-2.9 versions as well, since those versions don't
touch the result at all.

Change-Id: Iba6c1157e314088a90867292a4bd970bb873e284
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@nokia.com>