drm/amdgpu: fix addr handling in amdgpu_vm_bo_update_mapping

Otherwise we will look at the wrong place in the IB when GART
mappings are split into smaller updates.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Tom StDenis <Tom.StDenis@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c

@@ -1000,6 +1000,7 @@ static int amdgpu_vm_bo_update_mapping(struct amdgpu_device *adev,
 						    AMDGPU_GPU_PAGE_SIZE);
 			pte[i] |= flags;
 		}
+		addr = 0;
 	}
 
 	r = amdgpu_sync_fence(adev, &job->sync, exclusive);