Bluetooth: fix passkey uninitialized when used

This patch fix the issue: warning:variable 'passkey' is uninitialized
when used here

Link: https://groups.google.com/forum/#!topic/clang-built-linux/kyRKCjRsGoU

Fixes: cee5f20f ("Bluetooth: secure bluetooth stack from bluedump attack")
Reported-by: kbuild test robot <lkp@intel.com>
Suggested-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Howard Chung <howardchung@google.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

net/bluetooth/smp.c

@@ -2115,7 +2115,7 @@ static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
 	struct l2cap_chan *chan = conn->smp;
 	struct smp_chan *smp = chan->data;
 	struct hci_conn *hcon = conn->hcon;
-	u8 *pkax, *pkbx, *na, *nb;
+	u8 *pkax, *pkbx, *na, *nb, confirm_hint;
 	u32 passkey;
 	int err;
 
@@ -2179,13 +2179,12 @@ static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
 		 */
 		if (hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
 				 hcon->role)) {
-			err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst,
-							hcon->type,
-							hcon->dst_type,
-							passkey, 1);
-			if (err)
-				return SMP_UNSPECIFIED;
-			set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
+			/* Set passkey to 0. The value can be any number since
+			 * it'll be ignored anyway.
+			 */
+			passkey = 0;
+			confirm_hint = 1;
+			goto confirm;
 		}
 	}
 
@@ -2207,8 +2206,11 @@ static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
 	if (err)
 		return SMP_UNSPECIFIED;
 
+	confirm_hint = 0;
+
+confirm:
 	err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, hcon->type,
-					hcon->dst_type, passkey, 0);
+					hcon->dst_type, passkey, confirm_hint);
 	if (err)
 		return SMP_UNSPECIFIED;