Apply by doing:
       cd /usr/src
       patch -p0 < 002_vr.patch

Then build and install a new kernel.

Index: sys/dev/pci/if_vr.c
===================================================================
RCS file: /cvs/src/sys/dev/pci/if_vr.c,v
retrieving revision 1.127
retrieving revision 1.127.2.1
diff -u -p -r1.127 -r1.127.2.1
--- sys/dev/pci/if_vr.c 9 Feb 2013 19:17:52 -0000       1.127
+++ sys/dev/pci/if_vr.c 5 May 2013 11:05:49 -0000       1.127.2.1
@@ -1610,7 +1610,7 @@ vr_watchdog(struct ifnet *ifp)
        * some TX descriptors to reclaim, so check for that first.
        */
       vr_txeof(sc);
-       if (sc->vr_cdata.vr_tx_cnt == 0);
+       if (sc->vr_cdata.vr_tx_cnt == 0)
               return;

       ifp->if_oerrors++;