Bluetooth: Fix bt_skb_sendmmsg not allocating partial chunks

stable inclusion
from stable-v5.10.134
commit 14fc9233aa73e896d21a4998cdd453349a4baa8b
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5ZVR7

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=14fc9233aa73e896d21a4998cdd453349a4baa8b



--------------------------------

commit 29fb6083 upstream.

Since bt_skb_sendmmsg can be used with the likes of SOCK_STREAM it
shall return the partial chunks it could allocate instead of freeing
everything as otherwise it can cause problems like bellow.

Fixes: 81be03e0 ("Bluetooth: RFCOMM: Replace use of memcpy_from_msg with bt_skb_sendmmsg")
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Link: https://lore.kernel.org/r/d7206e12-1b99-c3be-84f4-df22af427ef5@molgen.mpg.de
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215594


Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Tested-by: Paul Menzel <pmenzel@molgen.mpg.de> (Nokia N9 (MeeGo/Harmattan)
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: Wei Li <liwei391@huawei.com>