crypto: atmel-aes - use swap()

Use swap() instead of implementing it in order to make code more clean.
Signed-off-by: Salah Triki <salah.triki@gmail.com>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/atmel-aes.c

@@ -1859,12 +1859,8 @@ static int atmel_aes_xts_process_data(struct atmel_aes_dev *dd)
 	 * the order of the ciphered tweak bytes need to be reversed before
 	 * writing them into the ODATARx registers.
 	 */
-	for (i = 0; i < AES_BLOCK_SIZE/2; ++i) {
-		u8 tmp = tweak_bytes[AES_BLOCK_SIZE - 1 - i];
-
-		tweak_bytes[AES_BLOCK_SIZE - 1 - i] = tweak_bytes[i];
-		tweak_bytes[i] = tmp;
-	}
+	for (i = 0; i < AES_BLOCK_SIZE/2; ++i)
+		swap(tweak_bytes[i], tweak_bytes[AES_BLOCK_SIZE - 1 - i]);
 
 	/* Process the data. */
 	atmel_aes_write_ctrl(dd, use_dma, NULL);