io_uring/net: clear msg_controllen on partial sendmsg retry

io_uring/net: clear msg_controllen on partial sendmsg retry

commit b1dc492087db0f2e5a45f1072a743d04618dd6be upstream.

If we have cmsg attached AND we transferred partial data at least, clear
msg_controllen on retry so we don't attempt to send that again.

Cc: stable@vger.kernel.org # 5.10+
Fixes: cac9e4418f4c ("io_uring/net: save msghdr->msg_control for retries")
Reported-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>