lsm: preserve /proc/sys/vm/mmap_min_addr when !CONFIG_SECURITY

lsm: preserve /proc/sys/vm/mmap_min_addr when !CONFIG_SECURITY

While reworking the LSM initialization code the
/proc/sys/vm/mmap_min_addr handler was inadvertently caught up in the
change and the procfs entry wasn't setup when CONFIG_SECURITY was not
selected at kernel build time.  This patch restores the previous behavior
and ensures that the procfs entry is setup regardless of the
CONFIG_SECURITY state.

Future work will improve upon this, likely by moving the procfs handler
into the mm subsystem, but this patch should resolve the immediate
regression.

Fixes: 4ab5efcc2829 ("lsm: consolidate all of the LSM framework initcalls")
Reported-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Tested-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>