[patch] drm/tegra: checking IS_ERR() instead of NULL

[Dan Carpenter]

iommu_domain_alloc() returns NULL on error, it never returns error
pointers.

Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>

diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
index e549afe..fa16048 100644
--- a/drivers/gpu/drm/tegra/drm.c
+++ b/drivers/gpu/drm/tegra/drm.c
@@ -36,8 +36,8 @@ static int tegra_drm_load(struct drm_device *drm, unsigned long flags)
 
 	if (iommu_present(&platform_bus_type)) {
 		tegra->domain = iommu_domain_alloc(&platform_bus_type);
-		if (IS_ERR(tegra->domain)) {
-			err = PTR_ERR(tegra->domain);
+		if (!tegra->domain) {
+			err = -ENOMEM;
 			goto free;
 		}