APPARMOR: Fix memory leak of alloc_namespace()

policy->name is a substring of policy->hname, if prefix is not NULL, it will
allocted strlen(prefix) + strlen(name) + 3 bytes to policy->hname in policy_init().
use kzfree(ns->base.name) will casue memory leak if alloc_namespace() failed.

Signed-off-by: Zhitong Wang <zhitong.wangzt@alibaba-inc.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>

security/apparmor/policy.c

@@ -306,7 +306,7 @@ static struct aa_namespace *alloc_namespace(const char *prefix,
 	return ns;
 
 fail_unconfined:
-	kzfree(ns->base.name);
+	kzfree(ns->base.hname);
 fail_ns:
 	kzfree(ns);
 	return NULL;