dma_buf_map_attachment() can return NULL and valid sg as return
value. Hence the check for the returned scatter-gather must be using
the inline function IS_ERR_OR_NULL() in place of IS_ERR()
Signed-off-by: NSubash Patel <subash.ramaswamy@linaro.org>
Signed-off-by: NInki Dae <inki.dae@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>