rtc: optee: Fix error code in optee_rtc_read_alarm()

Return "optee_alarm" instead of "alarm".  The "alarm" pointer is a valid
pointer and not an error pointer.

Fixes: 6266aea ("rtc: optee: add alarm related rtc ops to optee rtc driver")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/9e3718fe1128964907619ad325c0c5f5c1354ace.1758182509.git.dan.carpenter@linaro.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Author: Dan Carpenter

drivers/rtc/rtc-optee.c

@@ -299,7 +299,7 @@ static int optee_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 
 	optee_alarm = tee_shm_get_va(priv->shm, 0);
 	if (IS_ERR(optee_alarm))
-		return PTR_ERR(alarm);
+		return PTR_ERR(optee_alarm);
 
 	if (param[0].u.memref.size != sizeof(*optee_alarm))
 		return -EPROTO;