r600g: Use separate index_bias variable

Needed to get rid of a separate struct allocation in the next patch, because
the one in argument is a constant, and don't allow changing its fields.

Signed-off-by: Constantine Kharlamov <Hi-Angel@yandex.ru>
Signed-off-by: Marek Olšák <marek.olsak@amd.com>
1 file changed