drm/amdgpu: stop allocating a page array for prime shared BOs

We don't need the page array for prime shared BOs, stop allocating it.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Roger He <Hongbo.He@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
index 137145d..dc8d9f3 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
@@ -315,7 +315,7 @@ int amdgpu_gart_bind(struct amdgpu_device *adev, uint64_t offset,
 	t = offset / AMDGPU_GPU_PAGE_SIZE;
 	p = t / (PAGE_SIZE / AMDGPU_GPU_PAGE_SIZE);
 	for (i = 0; i < pages; i++, p++)
-		adev->gart.pages[p] = pagelist[i];
+		adev->gart.pages[p] = pagelist ? pagelist[i] : NULL;
 #endif
 
 	if (!adev->gart.ptr)