spi: spi_bfin: bugfix for 8..16 bit word sizes

Fix bug in u16_cs_chg_reader to read data_len-2 bytes data firstly, then read
out the last 2 bytes data
Signed-off-by: NBryan Wu <bryan.wu@analog.com>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/spi/spi_bfin5xx.c

@@ -501,7 +501,7 @@ static void u16_cs_chg_reader(struct driver_data *drv_data)
 	cs_active(drv_data, chip);
 	dummy_read(drv_data);
 
-	while (drv_data->rx < drv_data->rx_end) {
+	while (drv_data->rx < drv_data->rx_end - 2) {
 		cs_deactive(drv_data, chip);
 
 		if (chip->cs_chg_udelay)