[ Upstream commit 46273cf7e009231d2b6bc10a926e82b8928a9fb2 ]

genlmsg_put could fail. The fix inserts a check of its return value, and
if it fails, returns -EMSGSIZE.
Signed-off-by: NKangjie Lu <kjlu@umn.edu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>