st/nine: fix stack corruption due to ABI mismatch

st/nine: fix stack corruption due to ABI mismatch

This fixes various crashes and hangs when using nine's 'thread_submit'
feature.

On 64bit, the thread function's data argument would just be NULL.
On 32bit, the data argument would be garbage depending on the compiler
flags (in my case -march>=core2).

Fixes: f3fa7e3068512d ("st/nine: Use WINE thread for threadpool")
Cc: mesa-stable@lists.freedesktop.org
Signed-off-by: Andre Heider <a.heider@gmail.com>
Reviewed-by: Axel Davy <davyaxel0@gmail.com>