APPLIED: [SRU][P-ESM/T/Z][CVE-2017-11176][PATCH] mqueue: fix a use-after-free in sys_mq_notify()

[Thadeu Lima de Souza Cascardo]

Applied to trusty and zesty master-next branches.

Thanks.
Cascardo.

Applied-to: trusty/master-next
Applied-to: zesty/master-next