VNC_FEATURE_XVP was not shifted left before adding it to vs->features,
so it was never enabled; but it was also checked the wrong way with
a logical AND instead of vnc_has_feature. Fix both places.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 477b301000d665313217f65e3a368d2cb7769c42)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>