sys: fix doxygen grouping of tsrb und embUnit

sys/include/embUnit.h

@@ -9,9 +9,11 @@
 /**
  * @defgroup unittests Unittests
  * @ingroup  sys
+ * @brief RIOT Unittests based on the EmbUnit Framework
  *
- * @note
- * Please refer to https://github.com/RIOT-OS/RIOT/wiki/Testing-RIOT
+ * @see http://embunit.sourceforge.net/embunit/
+ *
+ * @note Please refer to https://github.com/RIOT-OS/RIOT/wiki/Testing-RIOT
  *
  * @author Martine Lenders <mlenders@inf.fu-berlin.de>
  */

sys/include/tsrb.h

@@ -9,17 +9,16 @@
 /**
  * @defgroup    sys_tsrb Thread safe ringbuffer
  * @ingroup     sys
+ * @brief       Thread-safe ringbuffer implementation
  * @{
- */
-
-/**
+ *
  * @file
- * @brief       Thread-safe ringbuffer implementation
+ * @brief       Thread-safe ringbuffer interface definition
  *
- * This ringbuffer implementation can be used without locking if
- * there's only one producer and one consumer.
+ * @note        This ringbuffer implementation can be used without locking if
+ *              there's only one producer and one consumer.
  *
- * @note Buffer size must be a power of two!
+ * @attention   Buffer size must be a power of two!
  *
  * @author      Kaspar Schleiser <kaspar@schleiser.de>
  */
@@ -150,5 +149,5 @@ int tsrb_add(tsrb_t *rb, const char *src, size_t n);
 }
 #endif
 
-/** @} */
 #endif /* TSRB_H */
+/** @} */