rtc: opal: fix type of token

The variable can take signed values.

The problem has been detected using proposed semantic patch
scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci [1].

[1]: http://permalink.gmane.org/gmane.linux.kernel/2038576

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

drivers/rtc/rtc-opal.c

@@ -152,10 +152,10 @@ exit:
 /* Set Timed Power-On */
 static int opal_set_tpo_time(struct device *dev, struct rtc_wkalrm *alarm)
 {
-	u64 h_m_s_ms = 0, token;
+	u64 h_m_s_ms = 0;
 	struct opal_msg msg;
 	u32 y_m_d = 0;
-	int rc;
+	int token, rc;
 
 	tm_to_opal(&alarm->time, &y_m_d, &h_m_s_ms);