mmc: dw_mmc: Stop bounce buffer even in case of failure

The driver didn't stop the bounce buffer in case a data transfer
failed. This would lead to memory leakage if the communication
between the CPU and the card is unreliable. Add the missing call
to stop the bounce buffer.
Signed-off-by: NMarek Vasut <marex@denx.de>
Cc: Dinh Nguyen <dinguyen@opensource.altera.com>
Cc: Pantelis Antoniou <panto@antoniou-consulting.com>
Cc: Tom Rini <trini@konsulko.com>

drivers/mmc/dw_mmc.c

@@ -215,6 +215,7 @@ static int dwmci_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
 			mask = dwmci_readl(host, DWMCI_RINTSTS);
 			if (mask & (DWMCI_DATA_ERR | DWMCI_DATA_TOUT)) {
 				printf("%s: DATA ERROR!\n", __func__);
+				bounce_buffer_stop(&bbstate);
 				return -1;
 			}
 		} while (!(mask & DWMCI_INTMSK_DTO));