anv: fix clflush usage on utrace copy batch
Signed-off-by:Lionel Landwerlin <lionel.g.landwerlin@intel.com> Fixes: cc5843a5 ("anv: implement u_trace support") Reviewed-by:
Marcin Ślusarz <marcin.slusarz@intel.com> Reviewed-by:
Tapani Pälli <tapani.palli@intel.com> Part-of: <mesa/mesa!15780> (cherry picked from commit 44e93b4c)