drm/panel: s6e8aa0: Fix build warnings on 64-bit

The %* format specifier expects an integer, which works fine with size_t
arguments on 32-bit because the types match. However on 64-bit, size_t
is typedef'd to unsigned long and will cause a build warning.

Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/gpu/drm/panel/panel-s6e8aa0.c b/drivers/gpu/drm/panel/panel-s6e8aa0.c
index 6427aa1..96f4476 100644
--- a/drivers/gpu/drm/panel/panel-s6e8aa0.c
+++ b/drivers/gpu/drm/panel/panel-s6e8aa0.c
@@ -143,8 +143,8 @@
 
 	ret = mipi_dsi_dcs_write(dsi, data, len);
 	if (ret < 0) {
-		dev_err(ctx->dev, "error %zd writing dcs seq: %*ph\n", ret, len,
-			data);
+		dev_err(ctx->dev, "error %zd writing dcs seq: %*ph\n", ret,
+			(int)len, data);
 		ctx->error = ret;
 	}
 }