drm/exynos: mic: fix an error code

We accidentally return success instead of a negative error code here.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/exynos_drm_mic.c

@@ -457,6 +457,7 @@ static int exynos_mic_probe(struct platform_device *pdev)
 							"samsung,disp-syscon");
 	if (IS_ERR(mic->sysreg)) {
 		DRM_ERROR("mic: Failed to get system register.\n");
+		ret = PTR_ERR(mic->sysreg);
 		goto err;
 	}