glx/glvnd: list the strcmp arguments in correct order

glx/glvnd: list the strcmp arguments in correct order

Currently, due to the inverse order, strcmp will produce negative result
when the needle is towards the start of the haystack. Thus on the next
iteration(s) we'll end up further towards the end and eventually fail to
locate the entry.

Cc: "12.0" <mesa-stable@lists.freedesktop.org>
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>
(cherry picked from commit 62b224d428e04760dc96afb93873d67683337f88)