[PATCH -next v2] drm/exynos/iommu: fix return value check in drm_create_iommu_mapping()

[Wei Yongjun]

From: Wei Yongjun <yongjun_...@trendmicro.com.cn>

In case of error, function arm_iommu_create_mapping() returns
ERR_PTR() and never returns NULL. The NULL test in the return
value check should be replaced with IS_ERR().

Signed-off-by: Wei Yongjun <yongjun_wei at trendmicro.com.cn>
---
 drivers/gpu/drm/exynos/exynos_drm_iommu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_iommu.c 
b/drivers/gpu/drm/exynos/exynos_drm_iommu.c
index 09db198..2482b7f 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_iommu.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_iommu.c
@@ -56,8 +56,8 @@ int drm_create_iommu_mapping(struct drm_device *drm_dev)
        mapping = arm_iommu_create_mapping(&platform_bus_type, priv->da_start,
                                                priv->da_space_size,
                                                priv->da_space_order);
-       if (!mapping)
-               return -ENOMEM;
+       if (IS_ERR(mapping))
+               return PTR_ERR(mapping);

        dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms),
                                        GFP_KERNEL);