dmaengine: sh: rcar-dmac: Check for error num after dma_set_max_seg_size

dmaengine: sh: rcar-dmac: Check for error num after dma_set_max_seg_size

As the possible failure of the dma_set_max_seg_size(), it should be
better to check the return value of the dma_set_max_seg_size().

Fixes: 97d49c59e219 ("dmaengine: rcar-dmac: set scatter/gather max segment size")
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20220111011239.452837-1-jiasheng@iscas.ac.cn
Signed-off-by: Vinod Koul <vkoul@kernel.org>