powerpc/rmu: Fix the error memory free parameters

There are error parameters should be corrected when
calling dma_free_coherent to free rmu rx-ring buffers
in fsl_open_inb_mbox() function.
Signed-off-by: Liu Gang <Gang.Liu@freescale.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>

arch/powerpc/sysdev/fsl_rmu.c

@@ -881,9 +881,9 @@ fsl_open_inb_mbox(struct rio_mport *mport, void *dev_id, int mbox, int entries)
 	rc = request_irq(IRQ_RIO_RX(mport), fsl_rio_rx_handler, 0,
 			 "msg_rx", (void *)mport);
 	if (rc < 0) {
-		dma_free_coherent(priv->dev, RIO_MSG_BUFFER_SIZE,
-			rmu->msg_tx_ring.virt_buffer[i],
-			rmu->msg_tx_ring.phys_buffer[i]);
+		dma_free_coherent(priv->dev,
+			rmu->msg_rx_ring.size * RIO_MAX_MSG_SIZE,
+			rmu->msg_rx_ring.virt, rmu->msg_rx_ring.phys);
 		goto out;
 	}