The usually way to get the btle lowpan private data is to use the
introduced lowpan_dev inline function. This patch will cleanup by using
lowpan_dev consequently.
Reviewed-by: NStefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: NAlexander Aring <alex.aring@gmail.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>