Delete bogus cpu-host-passthrough test

We test the same XML for a type='kvm' domain twice, once with
QEMU_CAPS_KVM (expecting success), once without (expecting failure).

The failure case relies on QEMU_CAPS_MACHINE_OPT not being set,
failing in qemuBuildObsoleteAccelArg.

Checking a domain-type error message in a cpu test is strange.
Delete the negative test to allow assuming QEMU_CAPS_MACHINE_OPT by
default.
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NAndrea Bolognani <abologna@redhat.com>

tests/qemuxml2argvtest.c

@@ -1715,7 +1715,6 @@ mymain(void)
     DO_TEST_FAILURE("cpu-host-model-nofallback", NONE);
     skipLegacyCPUs = false;
     DO_TEST("cpu-host-passthrough", QEMU_CAPS_KVM);
-    DO_TEST_FAILURE("cpu-host-passthrough", NONE);
     DO_TEST_FAILURE("cpu-qemu-host-passthrough", QEMU_CAPS_KVM);
 
     qemuTestSetHostArch(driver.caps, VIR_ARCH_S390X);