usb: Add nonblock argument to submit_int_msg

This will be used to implement non-blocking keyboard polling in case of
errors.

Signed-off-by: Michal Suchanek <msuchanek@suse.de>
diff --git a/common/usb.c b/common/usb.c
index 14b2752..d9bcb5a 100644
--- a/common/usb.c
+++ b/common/usb.c
@@ -192,12 +192,15 @@
  */
 
 /*
- * submits an Interrupt Message
+ * submits an Interrupt Message. Some drivers may implement non-blocking
+ * polling: when non-block is true and the device is not responding return
+ * -EAGAIN instead of waiting for device to respond.
  */
 int usb_int_msg(struct usb_device *dev, unsigned long pipe,
-		void *buffer, int transfer_len, int interval)
+		void *buffer, int transfer_len, int interval, bool nonblock)
 {
-	return submit_int_msg(dev, pipe, buffer, transfer_len, interval);
+	return submit_int_msg(dev, pipe, buffer, transfer_len, interval,
+			      nonblock);
 }
 
 /*