rtlwifi: rtl8192de: remove the useless value assignment

The variable u4tmp is overwritten by the following call and the assignment
is useless, so remove it.
Reported-by: Tosk Robot <tencent_os_robot@tencent.com>
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1605332735-9648-1-git-send-email-kaixuxia@tencent.com

drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c

@@ -2566,7 +2566,7 @@ static void _rtl92d_phy_lc_calibrate_sw(struct ieee80211_hw *hw, bool is2t)
 		}
 		RTPRINT(rtlpriv, FINIT, INIT_IQK,
 			"PHY_LCK finish delay for %d ms=2\n", timecount);
-		u4tmp = rtl_get_rfreg(hw, index, RF_SYN_G4, RFREG_OFFSET_MASK);
+		rtl_get_rfreg(hw, index, RF_SYN_G4, RFREG_OFFSET_MASK);
 		if (index == 0 && rtlhal->interfaceindex == 0) {
 			RTPRINT(rtlpriv, FINIT, INIT_IQK,
 				"path-A / 5G LCK\n");