at86rf230: make at86rf230_async_error inline

This patch makes the at86rf230_async_error inline. This function is
small enough to handle inline.
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Reviewed-by: Stefan Schmidt <s.schmidt@samsung.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/net/ieee802154/at86rf230.c

@@ -450,7 +450,7 @@ at86rf230_async_error_recover(void *context)
 	ieee802154_wake_queue(lp->hw);
 }
 
-static void
+static inline void
 at86rf230_async_error(struct at86rf230_local *lp,
 		      struct at86rf230_state_change *ctx, int rc)
 {