ieee802154: af_ieee802154: fix typo in comment.

Signed-off-by: Stefan Schmidt <stefan@osg.samsung.com>
Acked-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

include/net/af_ieee802154.h

 /*
- * IEEE 802.15.4 inteface for userspace
+ * IEEE 802.15.4 interface for userspace
  *
  * Copyright 2007, 2008 Siemens AG
  *