Clean up some potential memory leaks

The watchdog tasks are allocated, but not consistently removed. In
general this doesn't matter: they run in threads that will only
end when the process actually quits. For consistency and for the
purpose of future-proofing, I think there is value in having the
cleanup added in each case.

modules/database/src/ioc/as/asCa.c

@@ -225,6 +225,11 @@ static void asCaTask(void)
         if(asCaDebug) printf("asCaTask has cleared all channels\n");
         epicsEventSignal(asCaTaskWait);
     }
+
+    /* ATM never reached, just a placeholder */
+    cantProceed("Unreachable.  Perpetual thread.");
+
+    taskwdRemove(0);
 }
 
 void asCaStart(void)

modules/database/src/ioc/rsrv/caservertask.c

@@ -120,6 +120,11 @@ static void req_server (void *pParm)
             }
         }
     }
+
+    /* ATM never reached, just a placeholder */
+    cantProceed("Unreachable.  Perpetual thread.");
+
+    taskwdRemove(0);
 }
 
 static

modules/database/src/ioc/rsrv/online_notify.c

@@ -129,7 +129,11 @@ void rsrv_online_notify_task(void *pParm)
         }
     }
 
+    /* ATM never reached, just a placeholder */
+    cantProceed("Unreachable.  Perpetual thread.");
+
     free(lastError);
+    taskwdRemove(0);
 }