uip6: disable doxygen for disabled function
The doxygen documents a commented out function,
so turn the documentation into a regular comment.
@@ -1478,7 +1478,7 @@ extern uint8_t uip_flags;
too many retransmissions. */
-/**
+/*
* \brief process the options within a hop by hop or destination option header
* \retval 0: nothing to send,
* \retval 1: drop pkt
