staging/rtl8192e: use s8 instead of char

Compiling the rtlwifi drivers for ARM with gcc -Wextra warns about lots of
incorrect code that results from 'char' being unsigned here, e.g.

staging/rtl8192e/rtl8192e/r8192E_phy.c:1072:36: error: comparison is always false due to limited range of data type [-Werror=type-limits]
staging/rtl8192e/rtl8192e/r8192E_phy.c:1104:36: error: comparison is always false due to limited range of data type [-Werror=type-limits]
staging/rtl8192e/rtl8192e/rtl_core.c:1987:16: error: comparison is always false due to limited range of data type [-Werror=type-limits]
staging/rtl8192e/rtl8192e/rtl_dm.c:782:37: error: comparison is always false due to limited range of data type [-Werror=type-limits]
staging/rtl8192e/rtllib_softmac_wx.c:465:16: error: comparison is always false due to limited range of data type [-Werror=type-limits]

This patch changes all uses of 'char' in this driver that refer to
8-bit integers to use 's8' instead, which is signed on all architectures.

Signed-off-by: Arnd Bergmann <[e-mail]>
Acked-by: Jes Sorensen <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/rtl8192e/rtl8192e/r8192E_dev.c

···
 	struct phy_ofdm_rx_status_rxsc_sgien_exintfflag *prxsc;
 	u8 *prxpkt;
 	u8 i, max_spatial_stream, tmp_rxsnr, tmp_rxevm, rxsc_sgien_exflg;
-	char rx_pwr[4], rx_pwr_all = 0;
-	char rx_snrX, rx_evmX;
+	s8 rx_pwr[4], rx_pwr_all = 0;
+	s8 rx_snrX, rx_evmX;
 	u8 evm, pwdb_all;
 	u32 RSSI, total_rssi = 0;
 	u8 is_cck_rate = 0;
···
 				     2) - 110;
 
 			tmp_rxsnr = pofdm_buf->rxsnr_X[i];
-			rx_snrX = (char)(tmp_rxsnr);
+			rx_snrX = (s8)(tmp_rxsnr);
 			rx_snrX /= 2;
 			priv->stats.rxSNRdB[i] = (long)rx_snrX;
 
···
 
 		for (i = 0; i < max_spatial_stream; i++) {
 			tmp_rxevm = pofdm_buf->rxevm_X[i];
-			rx_evmX = (char)(tmp_rxevm);
+			rx_evmX = (s8)(tmp_rxevm);
 
 			rx_evmX /= 2;
 

drivers/staging/rtl8192e/rtl8192e/r8192E_phy.c

···
 {
 	struct r8192_priv *priv = rtllib_priv(dev);
 	u8	powerlevel = 0, powerlevelOFDM24G = 0;
-	char ant_pwr_diff;
+	s8	ant_pwr_diff;
 	u32	u4RegValue;
 
 	if (priv->epromtype == EEPROM_93C46) {

drivers/staging/rtl8192e/rtl8192e/rtl_core.c

···
 					weighting) / 6;
 }
 
-u8 rtl92e_rx_db_to_percent(char antpower)
+u8 rtl92e_rx_db_to_percent(s8 antpower)
 {
 	if ((antpower <= -100) || (antpower >= 20))
 		return	0;
···
 
 }	/* QueryRxPwrPercentage */
 
-u8 rtl92e_evm_db_to_percent(char value)
+u8 rtl92e_evm_db_to_percent(s8 value)
 {
-	char ret_val;
+	s8 ret_val;
 
 	ret_val = value;
 

drivers/staging/rtl8192e/rtl8192e/rtl_core.h

···
 	u32 Pwr_Track;
 	u8 CCKPresentAttentuation_20Mdefault;
 	u8 CCKPresentAttentuation_40Mdefault;
-	char CCKPresentAttentuation_difference;
-	char CCKPresentAttentuation;
+	s8 CCKPresentAttentuation_difference;
+	s8 CCKPresentAttentuation;
 	long undecorated_smoothed_pwdb;
 
 	u32 MCSTxPowerLevelOriginalOffset[6];
···
 long rtl92e_translate_to_dbm(struct r8192_priv *priv, u8 signal_strength_index);
 void rtl92e_update_rx_statistics(struct r8192_priv *priv,
 				 struct rtllib_rx_stats *pprevious_stats);
-u8 rtl92e_evm_db_to_percent(char value);
-u8 rtl92e_rx_db_to_percent(char antpower);
+u8 rtl92e_evm_db_to_percent(s8 value);
+u8 rtl92e_rx_db_to_percent(s8 antpower);
 void rtl92e_copy_mpdu_stats(struct rtllib_rx_stats *psrc_stats,
 			    struct rtllib_rx_stats *ptarget_stats);
 bool rtl92e_enable_nic(struct net_device *dev);