minor refactoring

src/shellmatta_transport.h

@@ -46,7 +46,6 @@
 #define SHELLMATTA_LENGTH_S2H_SEQUENCE_CNT  ((uint8_t)(1))
 /** @brief length of headerfield: crc32 of header + payload without crc32 */
 #define SHELLMATTA_LENGTH_CRC               ((uint8_t)(4))
-/** @} */
 
 /**
  * @brief definition of shellmatta transport layer states