rtw89: 8852c: fix warning of FIELD_PREP() mask type

To fix the compiler warning of clang with i386 config, but not complain
by gcc:

           __write_ctrl(R_AX_PWR_RATE_CTRL, B_AX_FORCE_PWR_BY_RATE_VALUE_MASK,
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/net/wireless/realtek/rtw89/rtw8852c.c:2621:13: note: expanded from macro '__write_ctrl'
           u32 _wrt = FIELD_PREP(__msk, _val);                     \
                      ^~~~~~~~~~~~~~~~~~~~~~~
   include/linux/bitfield.h:114:3: note: expanded from macro 'FIELD_PREP'
                   __BF_FIELD_CHECK(_mask, 0ULL, _val, "FIELD_PREP: ");    \
                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/bitfield.h:71:53: note: expanded from macro '__BF_FIELD_CHECK'
                   BUILD_BUG_ON_MSG(__bf_cast_unsigned(_mask, _mask) >     \
                   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
   note: (skipping 1 expansions in backtrace; use -fmacro-backtrace-limit=0 to see all)
   include/linux/compiler_types.h:352:22: note: expanded from macro 'compiletime_assert'
           _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
           ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/compiler_types.h:340:23: note: expanded from macro '_compiletime_assert'
           __compiletime_assert(condition, msg, prefix, suffix)
           ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/compiler_types.h:332:9: note: expanded from macro '__compiletime_assert'
                   if (!(condition))                                       \
                         ^~~~~~~~~
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220503120001.79272-8-pkshih@realtek.com

drivers/net/wireless/realtek/rtw89/rtw8852c.c

@@ -2616,16 +2616,14 @@ rtw8852c_btc_set_wl_txpwr_ctrl(struct rtw89_dev *rtwdev, u32 txpwr_val)
 
 #define __write_ctrl(_reg, _msk, _val, _en, _cond)		\
 do {								\
-	const typeof(_msk) __msk = _msk;			\
-	const typeof(_en) __en = _en;				\
-	u32 _wrt = FIELD_PREP(__msk, _val);			\
-	BUILD_BUG_ON((__msk & __en) != 0);			\
+	u32 _wrt = FIELD_PREP(_msk, _val);			\
+	BUILD_BUG_ON((_msk & _en) != 0);			\
 	if (_cond)						\
-		_wrt |= __en;					\
+		_wrt |= _en;					\
 	else							\
-		_wrt &= ~__en;					\
+		_wrt &= ~_en;					\
 	rtw89_mac_txpwr_write32_mask(rtwdev, RTW89_PHY_0, _reg,	\
-				     __msk | __en, _wrt);	\
+				     _msk | _en, _wrt);		\
 } while (0)
 
 	switch (arg.ctrl_all_time) {