audit: session ID should not set arch quick field pointer

A bug was introduced in 8fae4770
("audit: add support for session ID user filter")
See: https://github.com/linux-audit/audit-kernel/issues/4



When setting a session ID filter, the session ID filter field overwrote
the quick pointer reference to the arch field, potentially causing the
arch field to be misinterpreted.

Passes audit-testsuite.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>