wifi: rtw89: coex: Refine coexistence log

Adjust the log format and correct variable reference to make the log
more readable.

Signed-off-by: Ching-Te Ku <ku920601@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230117114109.4298-5-pkshih@realtek.com