media: amphion: fix UNUSED_VALUE issue reported by coverity

assign value '-EINVAL' to ret, but the stored value is overwritten
before it can be used

Fixes: 9f599f35 ("media: amphion: add vpu core driver")
Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Ming Qian <ming.qian@nxp.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

drivers/media/platform/amphion/vpu_cmds.c

@@ -313,7 +313,7 @@ static int vpu_session_send_cmd(struct vpu_inst *inst, u32 id, void *data)
 {
 	unsigned long key;
 	int sync = false;
-	int ret = -EINVAL;
+	int ret;
 
 	if (inst->id < 0)
 		return -EINVAL;