Bluetooth: Fix return value when bt_skb_alloc fails

Set the proper error(ENOMEM), instead of just return 0.

Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/drivers/bluetooth/hci_ll.c b/drivers/bluetooth/hci_ll.c
index 5c65014..91e44df 100644
--- a/drivers/bluetooth/hci_ll.c
+++ b/drivers/bluetooth/hci_ll.c
@@ -491,7 +491,7 @@
 			BT_ERR("Can't allocate mem for new packet");
 			ll->rx_state = HCILL_W4_PACKET_TYPE;
 			ll->rx_count = 0;
-			return 0;
+			return -ENOMEM;
 		}
 
 		ll->rx_skb->dev = (void *) hu->hdev;