+ * - value greater than 0 and rte_errno not changed - returned value is
+ * the number of canceled alarm callback functions
+ * - value greater or equal 0 and rte_errno set to EINPROGRESS, at least one
+ * alarm could not be canceled because cancellation was requested from alarm
+ * callback context. Returned value is the number of succesfuly canceled
+ * alarm callbacks
+ * - 0 and rte_errno set to ENOENT - no alarm found
+ * - -1 and rte_errno set to EINVAL - invalid parameter (NULL callback)