LSM: Convert security_initcall() into DEFINE_LSM()

Instead of using argument-based initializers, switch to defining the
contents of struct lsm_info on a per-LSM basis. This also drops
the final use of the now inaccurate "initcall" naming.

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: James Morris <james.morris@microsoft.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

security/apparmor/lsm.c

@@ -1606,4 +1606,6 @@ alloc_out:
 	return error;
 }
 
-security_initcall(apparmor_init);
+DEFINE_LSM(apparmor) = {
+	.init = apparmor_init,
+};