Simplify qsort() comparision function to just call strcmp()

As in fslsfonts!12 (merged), since this is comparing char values, it probably doesn't suffer from the overflow problem described in https://flak.tedunangst.com/post/subtraction-is-not-comparison but the fact that an unqualified char can be either signed or unsigned depending on the platform doesn't make me feel good about relying on char value subtraction either.