rtlwifi: Fix spelling mistake "cacluated" -> "calculated"

There are some spelling mistakes in the comments. Fix it.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Lv Ruyi <lv.ruyi@zte.com.cn>
Acked-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220408095803.2495336-1-lv.ruyi@zte.com.cn