sonypi: don't use flush_scheduled_work()

flush_scheduled_work() is deprecated and scheduled to be removed.
Directly flush sonypi_device.input_work on removal instead.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Mattia Dongili <malattia@linux.it>
diff --git a/drivers/char/sonypi.c b/drivers/char/sonypi.c
index 73f66d0..79e36c8 100644
--- a/drivers/char/sonypi.c
+++ b/drivers/char/sonypi.c
@@ -1434,7 +1434,7 @@
 	sonypi_disable();
 
 	synchronize_irq(sonypi_device.irq);
-	flush_scheduled_work();
+	flush_work_sync(&sonypi_device.input_work);
 
 	if (useinput) {
 		input_unregister_device(sonypi_device.input_key_dev);