Its value is alway set to mr->romd_mode, so the removed comparisons are
fully superseded by "a->mr == b->mr".

Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <1458900629-2334-3-git-send-email-famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>