eal/freebsd: fix lock in alarm callback

[ upstream commit fc6bdd5248e843ba1300c8d46d43b263b4a69438 ]

The spinlock should unlock when clock_gettime() failed. This patch
fixes it by invoking clock_gettime() before lock.

Fixes: 26021a7 ("eal/bsd: support alarm API")

Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>

lib/librte_eal/freebsd/eal_alarm.c

@@ -148,12 +148,12 @@ eal_alarm_callback(void *arg __rte_unused)
 	struct timespec now;
 	struct alarm_entry *ap;
 
-	rte_spinlock_lock(&alarm_list_lk);
-	ap = LIST_FIRST(&alarm_list);
-
 	if (clock_gettime(CLOCK_TYPE_ID, &now) < 0)
 		return;
 
+	rte_spinlock_lock(&alarm_list_lk);
+	ap = LIST_FIRST(&alarm_list);
+
 	while (ap != NULL && timespec_cmp(&now, &ap->time) >= 0) {
 		ap->executing = 1;
 		ap->executing_id = pthread_self();