Bug#834372: xdriinfo: libGL is too old.

[Alan Coopersmith <alan.coopersmith@oracle.com>]

The "libGL is too old." error occurs if the libGL does not provide
both the glXGetScreenDriver & glXGetDriverConfig functions.

Support for the "--help" option was added upstream in the xdriinfo 1.0.8
release (published today by X.Org), but the libGL compatibility check
happens before any argument processing occurs, so may not help in this case.

--
        -Alan Coopersmith-                 alan.coopersmith@oracle.com
         Oracle Solaris Engineering - https://blogs.oracle.com/solaris