qemu: fix domain device validation

When the virDomainCapsDeviceDefValidate() function returned an error
status (-1), we were aborting the function early, but returning the
default return value (0). This patch properly returns an error in that
case.
Reviewed-by: NCole Robinson <crobinso@redhat.com>
Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>

src/qemu/qemu_domain.c

@@ -7225,7 +7225,7 @@ qemuDomainDeviceDefValidate(const virDomainDeviceDef *dev,
     if ((ret = qemuDomainDeviceDefValidateAddress(dev, qemuCaps)) < 0)
         goto cleanup;
 
-    if (virDomainCapsDeviceDefValidate(domCaps, dev, def) < 0)
+    if ((ret = virDomainCapsDeviceDefValidate(domCaps, dev, def)) < 0)
         goto cleanup;
 
     switch ((virDomainDeviceType)dev->type) {