at86rf230: add missing error handling

This patch adds an async error handling function if sync state change
runs into a timeout. The async error handling function tries to recover
the phy state machine into a valid state.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/drivers/net/ieee802154/at86rf230.c b/drivers/net/ieee802154/at86rf230.c
index 6857038..44d2f1d 100644
--- a/drivers/net/ieee802154/at86rf230.c
+++ b/drivers/net/ieee802154/at86rf230.c
@@ -690,8 +690,10 @@
 
 	rc = wait_for_completion_timeout(&lp->state_complete,
 					 msecs_to_jiffies(100));
-	if (!rc)
+	if (!rc) {
+		at86rf230_async_error(lp, &lp->state, -ETIMEDOUT);
 		return -ETIMEDOUT;
+	}
 
 	return 0;
 }