Bluetooth: Directly close dlc for not yet started RFCOMM session

If the RFCOMM session has not yet been started (ie., session is
still in BT_BOUND state) when a dlc is closed, directly close and
unlink the dlc rather than sending a DISC frame that is never
sent.

This allows the dlci to be immediately reused rather than waiting
for a 20 second timeout.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Tested-By: NAlexander Holler <holler@ahsoftware.de>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

net/bluetooth/rfcomm/core.c

@@ -468,13 +468,19 @@ static int __rfcomm_dlc_close(struct rfcomm_dlc *d, int err)
 
 	switch (d->state) {
 	case BT_CONNECT:
-	case BT_CONFIG:
-		/* Fall through */
-
 	case BT_CONNECTED:
 		__rfcomm_dlc_disconn(d);
 		break;
 
+	case BT_CONFIG:
+		if (s->state != BT_BOUND) {
+			__rfcomm_dlc_disconn(d);
+			break;
+		}
+		/* if closing a dlc in a session that hasn't been started,
+		 * just close and unlink the dlc
+		 */
+
 	default:
 		rfcomm_dlc_clear_timer(d);