samples/damon/wsse: do not stop ctx for damon_call() failure

damon_call() failure was causing the context to be stopped, but
asynchronously by the kdamond thread.  To handle the race, the caller had
to stop the context.  damon_call() is updated to do the stop on its own. 
Remove the damon_stop() call from the damon_call() error handling.

Link: https://lore.kernel.org/[email protected]
Signed-off-by: SJ Park <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

samples/damon/wsse.c

@@ -93,10 +93,8 @@ static int damon_sample_wsse_start(void)
 	}
 	repeat_call_control.data = ctx;
 	err = damon_call(ctx, &repeat_call_control);
-	if (err) {
-		damon_stop(&ctx, 1);
+	if (err)
 		damon_destroy_ctx(ctx);
-	}
 	return err;
 }