modules-test: ui-spice-app is not built as module

$(call land, $(CONFIG_SPICE), $(CONFIG_GIO)) will never return "m" so
ui-spice-app is always linked into QEMU.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Miroslav Rezanina <mrezanin@redhat.com>
Message-id: 1566495734-23297-2-git-send-email-pbonzini@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>