tests: vhost-user: disable unless CONFIG_VHOST_NET

vhost-user depends on vhost-net. We should probably fix that.
For now, let's disable the test otherwise.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/tests/Makefile b/tests/Makefile
index 4063639..e6474ba 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -188,7 +188,9 @@
 check-qtest-i386-y += tests/pc-cpu-test$(EXESUF)
 check-qtest-i386-y += tests/q35-test$(EXESUF)
 gcov-files-i386-y += hw/pci-host/q35.c
+ifeq ($(CONFIG_VHOST_NET),y)
 check-qtest-i386-$(CONFIG_LINUX) += tests/vhost-user-test$(EXESUF)
+endif
 check-qtest-x86_64-y = $(check-qtest-i386-y)
 gcov-files-i386-y += i386-softmmu/hw/timer/mc146818rtc.c
 gcov-files-x86_64-y = $(subst i386-softmmu/,x86_64-softmmu/,$(gcov-files-i386-y))