RDMA/cma: Mark end of CMA ID messages

RDMA/cma: Mark end of CMA ID messages

[ Upstream commit e48e5e198fb6ec77c91047a694022f0fefa45292 ]

The commit 1a1c116f3dcf ("RDMA/netlink: Simplify the put_msg and put_attr")
removes nlmsg_len calculation in ibnl_put_attr causing netlink messages and
caused to miss source and destination addresses.

Fixes: 1a1c116f3dcf ("RDMA/netlink: Simplify the put_msg and put_attr")
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>