sys: xtimer: xtimer_set(): shoot directly if offset <= 1

sys/xtimer/xtimer_core.c

@@ -121,8 +121,10 @@ void xtimer_set(xtimer_t *timer, uint32_t offset)
     uint32_t target = xtimer_now() + offset;
 
     if (offset < XTIMER_BACKOFF) {
-        /* spin until timer should be run */
-        xtimer_spin_until(target);
+        if (offset > 1) {
+            /* spin until timer should be run */
+            xtimer_spin_until(target);
+        }
 
         _shoot(timer);
     }