vz: build fix for passing qemuCaps to virDomainDefParseNode

Missing piece for [1]

[1]: 577a1f98: qemu: Pass correct qemuCaps to virDomainDefParseNode
Signed-off-by: NNikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>

src/vz/vz_driver.c

@@ -2609,7 +2609,7 @@ vzDomainSnapshotCreateXML(virDomainPtr domain,
         parse_flags |= VIR_DOMAIN_SNAPSHOT_PARSE_VALIDATE;
 
     if (!(def = virDomainSnapshotDefParseString(xmlDesc, driver->caps,
-                                                driver->xmlopt, NULL,
+                                                driver->xmlopt, NULL, NULL,
                                                 parse_flags)))
         goto cleanup;