dmaengine: sh: rcar-dmac: Check for error num after setting mask

dmaengine: sh: rcar-dmac: Check for error num after setting mask

Because of the possible failure of the dma_supported(), the
dma_set_mask_and_coherent() may return error num.
Therefore, it should be better to check it and return the error if
fails.

Fixes: 40388eb67f97 ("dmaengine: rcar-dmac: Widen DMA mask to 40 bits")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20220106030939.2644320-1-jiasheng@iscas.ac.cn
Signed-off-by: Vinod Koul <vkoul@kernel.org>