selinux: fix memdup.cocci warnings

Use kmemdup rather than duplicating its implementation

Generated by: scripts/coccinelle/api/memdup.cocci

Fixes: c7c556f1 ("selinux: refactor changing booleans")
CC: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: kernel test robot <lkp@intel.com>
Signed-off-by: Julia Lawall <julia.lawall@inria.fr>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

security/selinux/ss/conditional.c

@@ -686,12 +686,11 @@ static int cond_bools_copy(struct hashtab_node *new, struct hashtab_node *orig,
 {
 	struct cond_bool_datum *datum;
 
-	datum = kmalloc(sizeof(struct cond_bool_datum), GFP_KERNEL);
+	datum = kmemdup(orig->datum, sizeof(struct cond_bool_datum),
+			GFP_KERNEL);
 	if (!datum)
 		return -ENOMEM;
 
-	memcpy(datum, orig->datum, sizeof(struct cond_bool_datum));
-
 	new->key = orig->key; /* No need to copy, never modified */
 	new->datum = datum;
 	return 0;