hw/net/vmxnet3: Fix leftover unregister_savevm

Commit 78dd48df3 reworked vmxnet3's live migration but left a straggling
unregister_savevm call.  Remove it, although it doesn't seem to have
any bad effect.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190822111218.12079-1-dgilbert@redhat.com>
Reviewed-by: Dmitry Fleytman <dmitry.fleytman@gmail.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

hw/net/vmxnet3.c

@@ -2242,13 +2242,10 @@ static void vmxnet3_instance_init(Object *obj)
 
 static void vmxnet3_pci_uninit(PCIDevice *pci_dev)
 {
-    DeviceState *dev = DEVICE(pci_dev);
     VMXNET3State *s = VMXNET3(pci_dev);
 
     VMW_CBPRN("Starting uninit...");
 
-    unregister_savevm(dev, "vmxnet3-msix", s);
-
     vmxnet3_net_uninit(s);
 
     vmxnet3_cleanup_msix(s);