greybus: core: make greybus_kill_gbuf not return a value

We can't do anything if killing a gbuf fails, so just make this function
"always" be successful.

At the same time, make the host controller function also be called
"kill_gbuf" to keep the terminology in sync.

Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Reviewed-by: Alex Elder <elder@linaro.org>
diff --git a/drivers/staging/greybus/operation.c b/drivers/staging/greybus/operation.c
index c94e509..9b889b1 100644
--- a/drivers/staging/greybus/operation.c
+++ b/drivers/staging/greybus/operation.c
@@ -175,7 +175,7 @@
 	ret = wait_for_completion_interruptible(&operation->completion);
 	/* If interrupted, cancel the in-flight buffer */
 	if (ret < 0)
-		ret = greybus_kill_gbuf(operation->request);
+		greybus_kill_gbuf(operation->request);
 	return ret;
 
 }
@@ -519,17 +519,10 @@
  */
 void gb_operation_cancel(struct gb_operation *operation)
 {
-	int ret;
-
 	operation->canceled = true;
-	ret = greybus_kill_gbuf(operation->request);
-	if (ret)
-		pr_warn("error %d killing request gbuf\n", ret);
-	if (operation->response) {
-		ret = greybus_kill_gbuf(operation->response);
-		if (ret)
-			pr_warn("error %d killing response gbuf\n", ret);
-	}
+	greybus_kill_gbuf(operation->request);
+	if (operation->response)
+		greybus_kill_gbuf(operation->response);
 }
 
 int gb_operation_init(void)