ieee802154: fix error return code in ieee802154_llsec_getparams()

ieee802154: fix error return code in ieee802154_llsec_getparams()

BugLink: https://bugs.launchpad.net/bugs/1933691
[ Upstream commit 373e864cf52403b0974c2f23ca8faf9104234555 ]

Fix to return negative error code -ENOBUFS from the error handling
case instead of 0, as done elsewhere in this function.

Fixes: 3e9c156e2c21 ("ieee802154: add netlink interfaces for llsec")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Link: https://lore.kernel.org/r/20210519141614.3040055-1-weiyongjun1@huawei.com
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>