mei: amthif: use service function to flush amthif queue

Replace open coded loop with an existing service function:
mei_io_list_flush

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/misc/mei/client.h b/drivers/misc/mei/client.h
index 96d5de0..bf2b0b1 100644
--- a/drivers/misc/mei/client.h
+++ b/drivers/misc/mei/client.h
@@ -45,6 +45,8 @@
 {
 	INIT_LIST_HEAD(&list->list);
 }
+void mei_io_list_flush(struct mei_cl_cb *list, struct mei_cl *cl);
+
 /*
  * MEI Host Client Functions
  */