egl: replace _eglInitDriver() with a simple variable

Signed-off-by: Eric Engestrom <eric@engestrom.ch>
Reviewed-by: Marcin Ślusarz <marcin.slusarz@intel.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6037>

src/egl/main/eglglobals.c

@@ -54,11 +54,10 @@ struct _egl_global _eglGlobal =
    .Mutex = &_eglGlobalMutex,
    .DisplayList = NULL,
    .DeviceList = &_eglSoftwareDevice,
-   .NumAtExitCalls = 3,
+   .NumAtExitCalls = 2,
    .AtExitCalls = {
       /* default AtExitCalls, called in reverse order */
       _eglFiniDevice, /* always called last */
-      _eglUnloadDrivers,
       _eglFiniDisplay,
    },