atmel_serial: fix broken RX buffer allocation

Introduced by atmel_serial-split-the-interrupt-handler.patch.

Thanks to michael <trimarchi@gandalf.sssup.it> for spotting it.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/serial/atmel_serial.c

@@ -1469,7 +1469,8 @@ static int __devinit atmel_serial_probe(struct platform_device *pdev)
 
 	if (!atmel_use_dma_rx(&port->uart)) {
 		ret = -ENOMEM;
-		data = kmalloc(ATMEL_SERIAL_RINGSIZE, GFP_KERNEL);
+		data = kmalloc(sizeof(struct atmel_uart_char)
+				* ATMEL_SERIAL_RINGSIZE, GFP_KERNEL);
 		if (!data)
 			goto err_alloc_ring;
 		port->rx_ring.buf = data;