wifi: rtw89: coex: use void pointer as temporal type to copy report

With void pointer, we don't need to cast to 'u8 *' by one by.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220913092546.43722-2-pkshih@realtek.com