conf: Use virDomainChrSourceDefNew for vhostuser

Rather than using VIR_ALLOC, use the New API since we already
use the virDomainChrSourceDefFree function when done.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>
Reviewed-by: NLaine Stump <laine@laine.org>
Reviewed-by: NMarc Hartmayer <mhartmay@linux.vnet.ibm.com>

src/conf/domain_conf.c

@@ -11138,7 +11138,7 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
             goto error;
         }
 
-        if (VIR_ALLOC(def->data.vhostuser) < 0)
+        if (!(def->data.vhostuser = virDomainChrSourceDefNew(xmlopt)))
             goto error;
 
         def->data.vhostuser->type = VIR_DOMAIN_CHR_TYPE_UNIX;