Revert "dmaengine: sh: rcar-dmac: With cyclic DMA residue 0 is valid"

This reverts commit 0c7a66e6849d205d4443ee7d8bdd39c43e0e36e1.
Link: https://patchwork.kernel.org/patch/10839055/
It included NULL access problem, therefore revert it.

Signed-off-by: Hiroyuki Yokoyama <hiroyuki.yokoyama.vx@renesas.com>