Bluetooth: Add paranoid check for existing LE and BR/EDR SMP channels

When the SMP channels have been already registered, then print out a
clear WARN_ON message that something went wrong. Also unregister the
existing channels in this case before trying to register new ones.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

net/bluetooth/smp.c

@@ -3072,6 +3072,12 @@ int smp_register(struct hci_dev *hdev)
 	if (!lmp_le_capable(hdev))
 		return 0;
 
+	if (WARN_ON(hdev->smp_data)) {
+		chan = hdev->smp_data;
+		hdev->smp_data = NULL;
+		smp_del_chan(chan);
+	}
+
 	chan = smp_add_cid(hdev, L2CAP_CID_SMP);
 	if (IS_ERR(chan))
 		return PTR_ERR(chan);
@@ -3091,6 +3097,12 @@ int smp_register(struct hci_dev *hdev)
 		return 0;
 	}
 
+	if (WARN_ON(hdev->smp_bredr_data)) {
+		chan = hdev->smp_bredr_data;
+		hdev->smp_bredr_data = NULL;
+		smp_del_chan(chan);
+	}
+
 	chan = smp_add_cid(hdev, L2CAP_CID_SMP_BREDR);
 	if (IS_ERR(chan)) {
 		int err = PTR_ERR(chan);