rtlwifi: Clean rtl_evm_db_to_percentage a bit

Signed-off-by: Priit Laes <plaes@plaes.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/rtlwifi/stats.c

@@ -39,15 +39,8 @@ EXPORT_SYMBOL(rtl_query_rxpwrpercentage);
 
 u8 rtl_evm_db_to_percentage(char value)
 {
-	char ret_val;
-	ret_val = value;
-
-	if (ret_val >= 0)
-		ret_val = 0;
-	if (ret_val <= -33)
-		ret_val = -33;
-	ret_val = 0 - ret_val;
-	ret_val *= 3;
+	char ret_val = clamp(-value, 0, 33) * 3;
+
 	if (ret_val == 99)
 		ret_val = 100;