dmaengine: at_hdmac: add missing kfree() call in at_dma_xlate()

dmaengine: at_hdmac: add missing kfree() call in at_dma_xlate()

commit e097eb7473d9e70da9e03276f61cd392ccb9d79f upstream.

If memory allocation for 'atslave' succeed, at_dma_xlate() doesn't have a
corresponding kfree() in exception handling. Thus add kfree() for this
function implementation.

Fixes: bbe89c8e3d59 ("at_hdmac: move to generic DMA binding")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20200817115728.1706719-4-yukuai3@huawei.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>