ieee802154: 6lowpan: fix error frag handling

This patch fixes the error handling for lowpan_xmit_fragment by replace
"-PTR_ERR" to "PTR_ERR". PTR_ERR returns already a negative errno code.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
1 file changed