[AUDIT] create context if auditing was ever enabled

Disabling audit at runtime by auditctl doesn't mean that we can
stop allocating contexts for new processes; we don't want to miss them
when that sucker is reenabled.

(based on work from Al Viro in the RHEL kernel series)

Signed-off-by: Eric Paris <eparis@redhat.com>

diff --cc kernel/audit.c
Simple merge

diff --cc kernel/auditsc.c
Simple merge