spi/xilinx: Code cleanup

On the transmission loop, check for remaining bytes at the loop
condition.

This way we can handle transmissions of 0 bytes and clean the code.
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-xilinx.c

@@ -248,7 +248,7 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
 	xspi->remaining_bytes = t->len;
 	reinit_completion(&xspi->done);
 
-	for (;;) {
+	while (xspi->remaining_bytes) {
 		u16 cr;
 		int n_words;
 
@@ -278,10 +278,6 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
 		/* Read out all the data from the Rx FIFO */
 		while (n_words--)
 			xspi->rx_fn(xspi);
-
-		/* See if there is more data to send */
-		if (xspi->remaining_bytes <= 0)
-			break;
 	}
 
 	return t->len - xspi->remaining_bytes;