wsp(4): Make evdev interface operational if sysmouse one is not opened

Before this change evdev interface sent only copy of data sent through
the sysmouse interface. It worked as /dev/wsp0 device node was
automatcaly opened by devd(8) with starting of moused(8).
Starting with 15.0 moused(8) does not open sysmouse interface by default
thus making wsp(4) device dysfunctional.
Fix it with adding extra checks of interfaces state.

MFC after:	1 week

sys/dev/usb/input/wsp.c

@@ -1068,6 +1068,10 @@ wsp_intr_callback(struct usb_xfer *xfer, usb_error_t error)
 		if (evdev_rcpt_mask & EVDEV_RCPT_HW_MOUSE) {
 			evdev_push_key(sc->sc_evdev, BTN_LEFT, ibt);
 			evdev_sync(sc->sc_evdev);
+			if ((sc->sc_fflags & FREAD) == 0 ||
+			     usb_fifo_put_bytes_max(
+			      sc->sc_fifo.fp[USB_FIFO_RX]) == 0)
+				goto tr_setup;
 		}
 #endif
 		sc->sc_status.flags &= ~MOUSE_POSCHANGED;
@@ -1357,7 +1361,12 @@ wsp_intr_callback(struct usb_xfer *xfer, usb_error_t error)
 	case USB_ST_SETUP:
 tr_setup:
 		/* check if we can put more data into the FIFO */
-		if (usb_fifo_put_bytes_max(
+		if (
+#ifdef EVDEV_SUPPORT
+		    ((evdev_rcpt_mask & EVDEV_RCPT_HW_MOUSE) != 0 &&
+		     (sc->sc_state & WSP_EVDEV_OPENED) != 0) ||
+#endif
+		    usb_fifo_put_bytes_max(
 		    sc->sc_fifo.fp[USB_FIFO_RX]) != 0) {
 			usbd_xfer_set_frame_len(xfer, 0,
 			    sc->tp_datalen);