rtlwifi: rtl8821ae: remove set but not used variable 'type' in translate_rx_signal_stuff

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/net/wireless/realtek/rtlwifi/rtl8821ae/trx.c: In function 'translate_rx_signal_stuff':
drivers/net/wireless/realtek/rtlwifi/rtl8821ae/trx.c:309:6: warning:
 variable 'type' set but not used [-Wunused-but-set-variable]

It never used since commit 21e4b072 ("rtlwifi: rtl8821ae: Move driver from
staging to regular tree")

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>