Fix a couple doxygen warnings

Warnings complained about undocumented parameters.

modules/libcom/src/osi/epicsMessageQueue.h

@@ -84,8 +84,8 @@ public:
 
     /**
      *  \brief Send a message or timeout.
-     *  \param message Pointer to the data to be sent.
-     *  \param messageSize How many bytes to send.
+     *  \param message Pointer to the message to be sent
+     *  \param messageSize The size of \p message
      *  \param timeout The timeout delay in seconds. A timeout of zero is
      *  equivalent to calling trySend(); NaN or any value too large to be
      *  represented to the target OS is equivalent to no timeout.
@@ -99,6 +99,9 @@ public:
 
     /**
      *  \brief Try to receive a message.
+     *  \param[out] message Output buffer to store the received message
+     *  \param size Size of the buffer pointed to by \p message
+     *
      *  If the queue holds at least one message,
      *  the first message on the queue is moved to the specified location
      *  and the length of that message is returned.
@@ -115,6 +118,9 @@ public:
 
     /**
      *  \brief Fetch the next message on the queue.
+     *  \param[out] message Output buffer to store the received message
+     *  \param size Size of the buffer pointed to by \p message
+     *
      *  Wait for a message to be sent if the queue is empty, then move
      *  the first message queued to the specified location.
      *
@@ -130,8 +136,8 @@ public:
 
     /**
      *  \brief Wait for and fetch the next message.
-     *  \param message Buffer to hold message.
-     *  \param size Bytes available in the buffer.
+     *  \param[out] message Output buffer to store the received message
+     *  \param size Size of the buffer pointed to by \p message
      *  \param timeout The timeout delay in seconds. A timeout of zero is
      *  equivalent to calling tryReceive(); NaN or any value too large to
      *  be represented to the target OS is equivalent to no timeout.