glx/dri: Fix DRI drawable release at MakeCurrent time

glx/dri: Fix DRI drawable release at MakeCurrent time

We want to release the drawables of the context we're coming from, but
we were releasing them from the context we're switching to. This is
probably not a big deal normally because both contexts are likely to be
on the same display, which is all that driReleaseDrawables is really
sensitive to. But if the contexts are on different Displays this would
go quite wrong.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/17176>