dmaengine: jz4780: fix resource leaks on error exit return

In two cases when jz4780_dma_setup_hwdesc fails, there is a memory
leak on the allocated desc and associated DMA pools on the error
exit return path.  Fix this by free'ing the resources before
returning.
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

drivers/dma/dma-jz4780.c

@@ -324,8 +324,10 @@ static struct dma_async_tx_descriptor *jz4780_dma_prep_slave_sg(
 					      sg_dma_address(&sgl[i]),
 					      sg_dma_len(&sgl[i]),
 					      direction);
-		if (err < 0)
+		if (err < 0) {
+			jz4780_dma_desc_free(&jzchan->desc->vdesc);
 			return NULL;
+		}
 
 		desc->desc[i].dcm |= JZ_DMA_DCM_TIE;
 
@@ -368,8 +370,10 @@ static struct dma_async_tx_descriptor *jz4780_dma_prep_dma_cyclic(
 	for (i = 0; i < periods; i++) {
 		err = jz4780_dma_setup_hwdesc(jzchan, &desc->desc[i], buf_addr,
 					      period_len, direction);
-		if (err < 0)
+		if (err < 0) {
+			jz4780_dma_desc_free(&jzchan->desc->vdesc);
 			return NULL;
+		}
 
 		buf_addr += period_len;