selinux: fix memory leak in netlabel code

Fix a memory leak in security_netlbl_sid_to_secattr() as reported here:
 * https://bugzilla.redhat.com/show_bug.cgi?id=352281

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
index d243ddc..66e013d 100644
--- a/security/selinux/netlabel.c
+++ b/security/selinux/netlabel.c
@@ -53,10 +53,11 @@
 	struct sk_security_struct *sksec = sk->sk_security;
 	struct netlbl_lsm_secattr secattr;
 
+	netlbl_secattr_init(&secattr);
+
 	rc = security_netlbl_sid_to_secattr(sid, &secattr);
 	if (rc != 0)
-		return rc;
-
+		goto sock_setsid_return;
 	rc = netlbl_sock_setattr(sk, &secattr);
 	if (rc == 0) {
 		spin_lock_bh(&sksec->nlbl_lock);
@@ -64,6 +65,8 @@
 		spin_unlock_bh(&sksec->nlbl_lock);
 	}
 
+sock_setsid_return:
+	netlbl_secattr_destroy(&secattr);
 	return rc;
 }