Remove useless maxadmin commands

The commands did nothing.

server/core/dcb.c

@@ -1915,16 +1915,6 @@ dprintOneDCB(DCB *pdcb, DCB *dcb)
     }
 }
 
-/*
- * @brief Print DCB list statistics
- *
- * @param       pdcb    DCB to print results to
- */
-void
-dprintDCBList(DCB *pdcb)
-{
-}
-
 /**
  * Diagnostic to print all DCB allocated in the system
  *

server/core/poll.c

@@ -1522,17 +1522,6 @@ void poll_fake_hangup_event(DCB *dcb)
     poll_add_event_to_dcb(dcb, NULL, ev);
 }
 
-/**
- * Print the event queue contents
- *
- * @param pdcb          The DCB to print the event queue to
- */
-void
-dShowEventQ(DCB *pdcb)
-{
-}
-
-
 /**
  * Print the event queue statistics
  *

server/core/session.c

@@ -460,16 +460,6 @@ printAllSessions()
     dcb_foreach(printAllSessions_cb, NULL);
 }
 
-/*
- * @brief Print session list statistics
- *
- * @param       pdcb    DCB to print results to
- */
-void
-dprintSessionList(DCB *pdcb)
-{
-}
-
 /** Callback for dprintAllSessions */
 bool dprintAllSessions_cb(DCB *dcb, void *data)
 {

server/modules/routing/debugcli/debugcmd.c

@@ -134,12 +134,6 @@ struct subcommand showoptions[] =
         {0, 0, 0}
     },
 #endif
-    {
-        "dcblist", 0, 0, dprintDCBList,
-        "Show DCB statistics",
-        "Show statistics for the list of all DCBs(descriptor control blocks)",
-        {0}
-    },
     {
         "dcbs", 0, 0, dprintAllDCBs,
         "Show all DCBs",
@@ -159,12 +153,6 @@ struct subcommand showoptions[] =
         "Show the epoll polling system statistics",
         {0, 0, 0}
     },
-    {
-        "eventq", 0, 0, dShowEventQ,
-        "Show event queue",
-        "Show the queue of events waiting to be processed",
-        {0, 0, 0}
-    },
     {
         "eventstats", 0, 0, dShowEventStats,
         "Show event queue statistics",
@@ -255,12 +243,6 @@ struct subcommand showoptions[] =
         "Show a single session in MaxScale, e.g. show session 5",
         {ARG_TYPE_SESSION, 0, 0}
     },
-    {
-        "sessionlist", 0, 0, dprintSessionList,
-        "Show session list statistics",
-        "Show statistics for the list of all sessions",
-        {0, 0, 0}
-    },
     {
         "sessions", 0, 0, dprintAllSessions,
         "Show all sessions",