mtd: rawnand: cs553x: simplify the return expression of cs553x_write_ctrl_byte()

Simplify the return expression.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Minghao Chi <chi.minghao@zte.com.cn>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220505022354.61458-1-chi.minghao@zte.com.cn