drm/panel: s6e8aa0: silence array overflow warning

Smatch complains that we are reading beyond the end of the array here:

	drivers/gpu/drm/panel/panel-s6e8aa0.c:852 s6e8aa0_read_mtp_id()
	warn: buffer overflow 's6e8aa0_variants' 4 <= 4

We set the error code, so it's not harmful but it looks like a return
was intended here so lets add that and silence the warning.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/gpu/drm/panel/panel-s6e8aa0.c

@@ -847,6 +847,7 @@ static void s6e8aa0_read_mtp_id(struct s6e8aa0 *ctx)
 	if (i >= ARRAY_SIZE(s6e8aa0_variants)) {
 		dev_err(ctx->dev, "unsupported display version %d\n", id[1]);
 		ctx->error = -EINVAL;
+		return;
 	}
 
 	ctx->variant = &s6e8aa0_variants[i];