wifi: rtl8xxxu: fix txdw7 assignment of TX DESC v3

Type of txdw7 is __le16, so assign __le32 is wrong. Also, the
TXDESC_ANTENNA_SELECT_C is defined for __le32, so shift 16 bits to fit
the value. Compile test only.

sparse warnings: (new ones prefixed by >>)
>> rtl8xxxu_core.c:5198:24: sparse: sparse: invalid assignment: |=
>> rtl8xxxu_core.c:5198:24: sparse: left side has type restricted __le16
>> rtl8xxxu_core.c:5198:24: sparse: right side has type restricted __le32

Reported-by: kernel test robot <[e-mail]>
Signed-off-by: Ping-Ke Shih <[e-mail]>
Tested-by: Bitterblue Smith <[e-mail]>
Signed-off-by: Kalle Valo <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c

···
 
 	tx_desc->txdw2 |= cpu_to_le32(TXDESC_ANTENNA_SELECT_A |
 				      TXDESC_ANTENNA_SELECT_B);
-	tx_desc->txdw7 |= cpu_to_le32(TXDESC_ANTENNA_SELECT_C);
+	tx_desc->txdw7 |= cpu_to_le16(TXDESC_ANTENNA_SELECT_C >> 16);
 }
 
 static void rtl8xxxu_tx(struct ieee80211_hw *hw,