media: staging: rkisp1: params: in the isr, return if buffer list is empty

Currently the code in the isr checks if the buffer list is not
empty before referencing a buffer and then check again if the
buffer is not NULL. Instead we can save one 'if' statement by
returning if the buffers list is empty.
Also remove non-helpful inline doc 'get one empty buffer'
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Acked-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/staging/media/rkisp1/rkisp1-params.c

@@ -1198,16 +1198,14 @@ void rkisp1_params_isr(struct rkisp1_device *rkisp1)
 		return;
 	}
 
-	/* get one empty buffer */
-	if (!list_empty(&params->params))
-		cur_buf = list_first_entry(&params->params,
-					   struct rkisp1_buffer, queue);
-
-	if (!cur_buf) {
+	if (list_empty(&params->params)) {
 		spin_unlock(&params->config_lock);
 		return;
 	}
 
+	cur_buf = list_first_entry(&params->params,
+				   struct rkisp1_buffer, queue);
+
 	new_params = (struct rkisp1_params_cfg *)(cur_buf->vaddr);
 
 	rkisp1_isp_isr_other_config(params, new_params);