[ARM] rtc-pcf8583: don't use BCD_TO_BIN/BIN_TO_BCD

Both BCD_TO_BIN(x) and BIN_TO_BCD(x) have an unexpected side-effect -
not only do they return the value as expected, they _modify_ their
argument in the process.

Let's play it safe and avoid these macros.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

drivers/rtc/rtc-pcf8583.c

@@ -81,11 +81,11 @@ static int pcf8583_get_datetime(struct i2c_client *client, struct rtc_time *dt)
 		buf[4] &= 0x3f;
 		buf[5] &= 0x1f;
 
-		dt->tm_sec = BCD_TO_BIN(buf[1]);
-		dt->tm_min = BCD_TO_BIN(buf[2]);
-		dt->tm_hour = BCD_TO_BIN(buf[3]);
-		dt->tm_mday = BCD_TO_BIN(buf[4]);
-		dt->tm_mon = BCD_TO_BIN(buf[5]);
+		dt->tm_sec = BCD2BIN(buf[1]);
+		dt->tm_min = BCD2BIN(buf[2]);
+		dt->tm_hour = BCD2BIN(buf[3]);
+		dt->tm_mday = BCD2BIN(buf[4]);
+		dt->tm_mon = BCD2BIN(buf[5]);
 	}
 
 	return ret == 2 ? 0 : -EIO;
@@ -99,14 +99,14 @@ static int pcf8583_set_datetime(struct i2c_client *client, struct rtc_time *dt,
 	buf[0] = 0;
 	buf[1] = get_ctrl(client) | 0x80;
 	buf[2] = 0;
-	buf[3] = BIN_TO_BCD(dt->tm_sec);
-	buf[4] = BIN_TO_BCD(dt->tm_min);
-	buf[5] = BIN_TO_BCD(dt->tm_hour);
+	buf[3] = BIN2BCD(dt->tm_sec);
+	buf[4] = BIN2BCD(dt->tm_min);
+	buf[5] = BIN2BCD(dt->tm_hour);
 
 	if (datetoo) {
 		len = 8;
-		buf[6] = BIN_TO_BCD(dt->tm_mday) | (dt->tm_year << 6);
-		buf[7] = BIN_TO_BCD(dt->tm_mon)  | (dt->tm_wday << 5);
+		buf[6] = BIN2BCD(dt->tm_mday) | (dt->tm_year << 6);
+		buf[7] = BIN2BCD(dt->tm_mon)  | (dt->tm_wday << 5);
 	}
 
 	ret = i2c_master_send(client, (char *)buf, len);