winsys/radeon: fix relocs caching

Don't cache pointers to elements of reallocatable array.
In some circumstances it caused false cache hits resulting in incorrect
command stream and gpu lockup.

Note: This is a candidate for the stable branches.

Signed-off-by: Vadim Girlin <vadimgirlin@gmail.com>
Reviewed-by: Marek Olšák <maraeo@gmail.com>
2 files changed