qemu: Do not skip virCPUUpdateLive if priv->origCPU is set

qemu: Do not skip virCPUUpdateLive if priv->origCPU is set

Even though we got both the original CPU (used for starting a domain)
and the updated version (the CPU really provided by QEMU) during
incoming migration, restore, or snapshot revert, we still need to update
the CPU according to the data we got from the freshly started QEMU.
Otherwise we don't know whether the CPU we got from QEMU matches the one
before migration. We just need to keep the original CPU in
priv->origCPU.

Messed up by me in v3.4.0-58-g8e34f4781.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>