rtlwifi: fix build warning

Tasklet conversion patch introduced a build
warning in _rtl_usb_init_rx, this patch fixes the warning.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: d3ccc14dfe ("rtlwifi/rtw88: convert tasklets to use new tasklet_setup() API")
Signed-off-by: Allen Pais <allen.lkml@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200831043659.281712-1-allen.lkml@gmail.com

drivers/net/wireless/realtek/rtlwifi/usb.c

@@ -310,7 +310,8 @@ static int _rtl_usb_init_rx(struct ieee80211_hw *hw)
 	init_usb_anchor(&rtlusb->rx_cleanup_urbs);
 
 	skb_queue_head_init(&rtlusb->rx_queue);
-	rtlusb->rx_work_tasklet.func = (void(*)(unsigned long))_rtl_rx_work;
+	rtlusb->rx_work_tasklet.func = (void(*))_rtl_rx_work;
+	rtlusb->rx_work_tasklet.data = (unsigned long)&rtlusb->rx_work_tasklet;
 
 	return 0;
 }