i965/perf: fix config registration when uploading to kernel

When registring configurations to the kernel for the first time, we
run into an issue where the id number is not properly set (we're using
the wrong variable). As a result when trying to use that id later on,
we get an error.

This issue manifest itself the first time you use frameretrace after
reboot, subsequent runs are fine.

Fixes: 27ee83ea ("i965: perf: add support for userspace configurations")
Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
(cherry picked from commit 1603ce19)
[Juan A. Suarez: resolve trivial conflicts]
Signed-off-by: Juan A. Suarez Romero <jasuarez@igalia.com>

Conflicts:
	src/mesa/drivers/dri/i965/brw_performance_query.c