Ahh, I wondered if this was the same problem as in that thread. Guess so.
Anyway, it doesn't change any files anywhere. All you did was set an environment variable. I don't really know of any way to test it, either, other than just looking at a GL program's output and seeing if it looks to be antialiased.
You might be able to strace the program, too, and look for calls to getenv("__GL_FSAA_MODE"), to make sure that the library is actually using the environment variable's value. But if it is, I'm not sure what to try.
Maybe it's the aniso texture filtering? You can try the __GL_LOG_ANISO variable, too. Might help.