Bluetooth: RFCOMM: fix ODEBUG bug in rfcomm_dev_ioctl

Bluetooth: RFCOMM: fix ODEBUG bug in rfcomm_dev_ioctl

BugLink: https://bugs.launchpad.net/bugs/1873043
commit 71811cac8532b2387b3414f7cd8fe9e497482864 upstream.

Needn't call 'rfcomm_dlc_put' here, because 'rfcomm_dlc_exists' didn't
increase dlc->refcnt.

Reported-by: syzbot+4496e82090657320efc6@syzkaller.appspotmail.com
Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Suggested-by: Hillf Danton <hdanton@sina.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>