ieee802154: don't export static symbol

The semantic patch that fixes this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r@
type T;
identifier f;
@@

static T f (...) { ... }

@@
identifier r.f;
declarer name EXPORT_SYMBOL;
@@

-EXPORT_SYMBOL(f);
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

net/ieee802154/nl-mac.c

@@ -76,7 +76,6 @@ nla_put_failure:
 	nlmsg_free(msg);
 	return -ENOBUFS;
 }
-EXPORT_SYMBOL(ieee802154_nl_start_confirm);
 
 static int ieee802154_nl_fill_iface(struct sk_buff *msg, u32 portid,
 				    u32 seq, int flags, struct net_device *dev)