Don't leak work queue items in gss-server

On accept() failure in gss-server.c, we would leak the freshly
allocated work item.

src/appl/gss-sample/gss-server.c

@@ -781,6 +781,7 @@ main(int argc, char **argv)
                 /* Accept a TCP connection */
                 if ((work->s = accept(stmp, NULL, 0)) < 0) {
                     perror("accepting connection");
+                    free(work);
                     continue;
                 }