Bug 72380 - Never drop first font when trimming

Let me show it with an example.

Currently:

$ fc-match symbol
symbol.ttf: "Symbol" "Regular"

$ fc-match symbol --sort | head -n 1
Symbol.pfb: "Symbol" "Regular"

$ fc-match symbol --sort --all | head -n 1
symbol.ttf: "Symbol" "Regular"

I want to make sure the above three commands all return the same font.
Ie.  I want to make sure FcFontMatch() always returns the first font
from FcFontSort().  As such, never trim first font.
Fix a typo
Fix a build issue on platforms where doesn't support readlink()