HPCC-22487 Wait_multiple to return > 0 with readySocks if POLLNVAL set

Signed-off-by: Mark Kelly <mark.kelly@lexisnexisrisk.com>

system/jlib/jsocket.cpp

@@ -6728,7 +6728,7 @@ int wait_multiple(bool isRead,               //IN   true if wait read, false it
 #ifdef _USE_SELECT
             if (FD_ISSET(s, &fds))
 #else
-            if ( (fds[idx].revents) && (!(fds[idx].revents & POLLNVAL)) )
+            if (fds[idx].revents)
 #endif
             {
 #ifdef _DEBUG