Fix libGL.a check on configure

[Alexandre Julliard]

Anderson Lizardo <andersonlizardo at yahoo.com.br> writes:

> What about the attached patch? It uses "ls" instead of "test" to test
> for file presence (assuming ls returns non-zero code on a non-present
> file, which is true for a POSIX compliant system).

It would be much better to try the actual linking and see what
happens.

-- 
Alexandre Julliard
julliard at winehq.org