svga: Check rasterization state object before checking poly_stipple_enable

Sometimes rasterization state object could be empty. This is causing
segfault on hw8,9,10 for some traces.

This patch fixes enemy_territory_quake_wars_high,
enemy_territory_quake_wars_low, etqw-demo, lightsmark2008, quake1
glretrace crashes on hw 8,9,10.

Tested with mtt-glretrace and mtt-piglit.

Reviewed-by: Charmaine Lee <[email protected]>
Reviewed-by: Brian Paul <[email protected]>

0 files changed, 0 insertions, 0 deletions