io_uring/net: clear msg_controllen on partial sendmsg retry

stable inclusion
from stable-v5.10.186
commit 826ee9fa3647785e45ca87aa70511b72d25c2588
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8L5XP

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=826ee9fa3647785e45ca87aa70511b72d25c2588



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Commit b1dc4920 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: cac9e441 ("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>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>