drm/msm: Fix IS_ERR_OR_NULL() vs NULL check in a5xx_submit_in_rb()

The msm_gem_get_vaddr() returns an ERR_PTR() on failure, and a null
is catastrophic here, so we should use IS_ERR_OR_NULL() to check
the return value.

Fixes: 6a8bd08d04 ("drm/msm: add sudo flag to submit ioctl")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/547712/
Signed-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/adreno/a5xx_gpu.c

@@ -89,7 +89,7 @@ static void a5xx_submit_in_rb(struct msm_gpu *gpu, struct msm_gem_submit *submit
 			 * since we've already mapped it once in
 			 * submit_reloc()
 			 */
-			if (WARN_ON(!ptr))
+			if (WARN_ON(IS_ERR_OR_NULL(ptr)))
 				return;
 
 			for (i = 0; i < dwords; i++) {