Fix virNodeDeviceListCaps always returns empty

virNodeDeviceListCaps will always return empty for a pci nodedevice,
actually it should return 'pci'.

It is because the loop variable ncaps isn't increased.

Introduced by commit be2636f.

https://bugzilla.redhat.com/show_bug.cgi?id=1081932

Signed-off-by: Jincheng Miao <jmiao@redhat.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>

src/node_device/node_device_driver.c

@@ -420,7 +420,7 @@ nodeDeviceListCaps(virNodeDevicePtr dev, char **const names, int maxnames)
         goto cleanup;
 
     for (caps = obj->def->caps; caps && ncaps < maxnames; caps = caps->next) {
-        if (VIR_STRDUP(names[ncaps], virNodeDevCapTypeToString(caps->type)) < 0)
+        if (VIR_STRDUP(names[ncaps++], virNodeDevCapTypeToString(caps->type)) < 0)
             goto cleanup;
     }
     ret = ncaps;