dri3: annotate the dri3_screen_info data as const

dri3_screen_info is the user provide dispatch. Something that we do
not and should not change.

When using the _ptr typecast + const the compiler barfs at us
(rightfully so), so use the _rec one.

[Silence a new const mismatch warning too - ajax]

Fixes: 5631382988 ("dri3: Add DRI3 extension")
Cc: Keith Packard <keithp@keithp.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>

dri3/dri3.c

@@ -45,7 +45,7 @@ dri3_close_screen(ScreenPtr screen)
 }
 
 Bool
-dri3_screen_init(ScreenPtr screen, dri3_screen_info_ptr info)
+dri3_screen_init(ScreenPtr screen, const dri3_screen_info_rec *info)
 {
     dri3_screen_generation = serverGeneration;