mesa: set override_version per api version override

mesa: set override_version per api version override

Before 9b5e92f get_gl_override was called only once, but now it is
called for multiple APIs (GLES2, GL), version needs to be set always.

Signed-off-by: Tapani Pälli <tapani.palli@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=90797
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Martin Peres <martin.peres@linux.intel.com>
Tested-by: Martin Peres <martin.peres@linux.intel.com>