dmaengine: imx-sdma: Fix a possible memory leak in sdma_transfer_init

If the function sdma_load_context() fails, the sdma_desc will be
freed, but the allocated desc->bd is forgot to be freed.

We already met the sdma_load_context() failure case and the log as
below:
[ 450.699064] imx-sdma 30bd0000.dma-controller: Timeout waiting for CH0 ready
...

In this case, the desc->bd will not be freed without this change.

Signed-off-by: Hui Wang <hui.wang@canonical.com>
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
Link: https://lore.kernel.org/r/20221130090800.102035-1-hui.wang@canonical.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Author: jason77-wang

drivers/dma/imx-sdma.c

@@ -1521,10 +1521,12 @@ static struct sdma_desc *sdma_transfer_init(struct sdma_channel *sdmac,
 		sdma_config_ownership(sdmac, false, true, false);
 
 	if (sdma_load_context(sdmac))
-		goto err_desc_out;
+		goto err_bd_out;
 
 	return desc;
 
+err_bd_out:
+	sdma_free_bd(desc);
 err_desc_out:
 	kfree(desc);
 err_out: