[asan][test] Fix typo in Unit/lit.site.cfg.py.in

I noticed that `test/asan/Unit/lit.site.cfg.py.in` contains two typos,
using the FreeBSD forms of the `LD_*LIBRARY_PATH*` variables on Solaris.

Tested on `amd64-pc-solaris2.11`.

Differential Revision: https://reviews.llvm.org/D132736