BugLink: https://bugs.launchpad.net/bugs/1868627

[ Upstream commit 718eae27 ]

Convert cpu_to_le16(le16_to_cpu(frame->datalen) + len) to
use le16_add_cpu(), which is more concise and does the same thing.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Mao Wenan <maowenan@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>