UPSTREAM: net: remove cmsg restriction from io_uring based send/recvmsg calls

[ Upstream commit e5493796 ]

No need to restrict these anymore, as the worker threads are direct
clones of the original task. Hence we know for a fact that we can
support anything that the regular task can.

Since the only user of proto_ops->flags was to flag PROTO_CMSG_DATA_ONLY,
kill the member and the flag definition too.

Change-Id: Ie87e4ff3c621cf53a8e9589a7689e62d759de983
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit a3025359)
Bug: 268174392
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>