bonding: fix miimon failure counter

During the rework of the mii monitor for:

  commit f0c76d61
  Author: Jay Vosburgh <fubar@us.ibm.com>
  Date:   Wed Jul 2 18:21:58 2008 -0700

    bonding: refactor mii monitor

I left out the increment of the link failure counter.  This
patch corrects that omission.
Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/net/bonding/bond_main.c

@@ -2376,6 +2376,9 @@ static void bond_miimon_commit(struct bonding *bond)
 			continue;
 
 		case BOND_LINK_DOWN:
+			if (slave->link_failure_count < UINT_MAX)
+				slave->link_failure_count++;
+
 			slave->link = BOND_LINK_DOWN;
 
 			if (bond->params.mode == BOND_MODE_ACTIVEBACKUP ||