drm: Convert to devm_ioremap_resource()

Convert all uses of devm_request_and_ioremap() to the newly introduced
devm_ioremap_resource() which provides more consistent error handling.

devm_ioremap_resource() provides its own error messages so all explicit
error messages can be removed from the failure code paths.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Cc: David Airlie <airlied@linux.ie>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/gpu/drm/exynos/exynos_drm_fimc.c b/drivers/gpu/drm/exynos/exynos_drm_fimc.c
index 67a83e6..411f69b7 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_fimc.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_fimc.c
@@ -1785,11 +1785,9 @@
 
 	/* resource memory */
 	ctx->regs_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	ctx->regs = devm_request_and_ioremap(dev, ctx->regs_res);
-	if (!ctx->regs) {
-		dev_err(dev, "failed to map registers.\n");
-		return -ENXIO;
-	}
+	ctx->regs = devm_ioremap_resource(dev, ctx->regs_res);
+	if (IS_ERR(ctx->regs))
+		return PTR_ERR(ctx->regs);
 
 	/* resource irq */
 	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);