wifi: rtlwifi: rtl8821ae: phy: remove some useless code

Clang static checker warns:

Value stored to 'v1' is never read [deadcode.DeadStores]
Value stored to 'channel' is never read [deadcode.DeadStores]

Remove them to save some place.

Signed-off-by: Su Hui <suhui@nfschina.com>
Acked-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20231127013511.26694-1-suhui@nfschina.com