drivers/wireless/bluetooth/bt_uart_bcm4343x.c: Fix small a small bug

found during testing.
drivers/wireless/bluetooth/bt_uart_shim.c:  Change the task tname for
the HCI receiver task to bring it into line with the transmitter task.

drivers/wireless/bluetooth/bt_uart_bcm4343x.c

@@ -401,6 +401,7 @@ static int load_bcm4343x_firmware(FAR const struct btuart_lowerhalf_s *lower)
     }
 
   load_bcm4343x_firmware_finished:
+  lower->rxenable(lower, false);
   lower->rxattach(lower, NULL, NULL);
 
   return ret;

drivers/wireless/bluetooth/bt_uart_shim.c

@@ -471,7 +471,7 @@ FAR void *bt_uart_shim_getdevice(FAR char *path)
 
   s->enabled = true;
 
-  s->serialmontask = kthread_create("HCICollect",
+  s->serialmontask = kthread_create("BT HCI Rx",
                                     CONFIG_BLUETOOTH_TXCONN_PRIORITY,
                                     1024, hcicollecttask, NULL);