virSecurityDeviceLabelDefNew: Avoid NULL dereference

While it is impossible for VIR_ALLOC() to return an error, we
should be consistent with the rest of the code and not continue
initializing the virSecurityDeviceLabelDef structure.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

src/util/virseclabel.c

@@ -77,7 +77,7 @@ virSecurityDeviceLabelDefNew(const char *model)
 
     if (VIR_ALLOC(seclabel) < 0) {
         virSecurityDeviceLabelDefFree(seclabel);
-        seclabel = NULL;
+        return NULL;
     }
 
     seclabel->model = g_strdup(model);