Merge pull request #4940 from OlegHahm/xtimer_msg_receive_timeout_doc

tests xtimer: update documentation xtimer_msg_receive_timeout

tests/xtimer_msg_receive_timeout/main.c

@@ -13,6 +13,12 @@
  * @file
  * @brief       test application for xtimer_msg_receive_timeout()
  *
+ *              This test will start sequentially start 10 xtimers to send a
+ *              IPC msg, alternating with an interval of 900ms and 1100ms
+ *              respectively. Everytime a timer was set, it will wait for a
+ *              message for at most 1000ms. This should succeed and fail in an
+ *              alternating manner.
+ *
  * @author      Oliver Hahm <oliver.hahm@inria.fr>
  *
  * @}
@@ -39,7 +45,7 @@ int main(void)
             printf("Message received: %" PRIu16 "\n", m.type);
         }
         offset = (offset < 0) ? 1000 : -1000;
+        xtimer_remove(&t);
     }
-    xtimer_remove(&t);
     return 0;
 }