drm/stm: ltdc: Remove unnecessary platform_get_resource() error check

devm_ioremap_resource() already checks if the resource is NULL, so
remove the unnecessary platform_get_resource() error check.

Cc: Philippe Cornu <[e-mail]>
Signed-off-by: Fabio Estevam <[e-mail]>
Acked-by: Philippe Cornu <[e-mail]>
Signed-off-by: Benjamin Gaignard <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/stm/ltdc.c

···
 	}
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res) {
-		DRM_ERROR("Unable to get resource\n");
-		ret = -ENODEV;
-		goto err;
-	}
-
 	ldev->regs = devm_ioremap_resource(dev, res);
 	if (IS_ERR(ldev->regs)) {
 		DRM_ERROR("Unable to get ltdc registers\n");