ipcns: fix use after free in free_ipc_ns()
ipcns: fix use after free in free_ipc_ns()

commit b515498 ("userns: add a user namespace owner of ipc ns") added a
user namespace owner of ipc ns, but it also introduced a use after free in
free_ipc_ns().

Signed-off-by: Xiaotian Feng <27256e509c4df1bb795f8fd5fce61b94794f2db5@redhat.com>
Acked-by: "Serge E. Hallyn" <3df611b026e4639bee8aef7a4beb2e39fcebb313@canonical.com>
Acked-by: David Howells <ebac1d06c1688626821bb0e574a037a7a5354e49@redhat.com>
Cc: "Eric W. Biederman" <8a741aa8cbd77ebc4a56ddb528ce9fd15d42f034@xmission.com>
Cc: Daniel Lezcano <e9fa45941f2ebe89c1b9d6c5f339ab42eadb8567@free.fr>
Signed-off-by: Andrew Morton <5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org>
Signed-off-by: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>

KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas