net: Fix typo in net_device_ops description.

Signed-off-by: NMike Rapoport <mike@compulab.co.il>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/linux/netdevice.h

@@ -500,7 +500,7 @@ struct netdev_queue {
  *
  * int (*ndo_set_mac_address)(struct net_device *dev, void *addr);
  *	This function  is called when the Media Access Control address
- *	needs to be changed. If not this interface is not defined, the
+ *	needs to be changed. If this interface is not defined, the
  *	mac address can not be changed.
  *
  * int (*ndo_validate_addr)(struct net_device *dev);