We unconditionally set HTT, so merely doubling the value read from
hardware isn't going to be correct if that value is zero.
Reported-by: Julien Grall <julien@xen.org>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Julien Grall <julien@xen.org>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>