iw_cxgb4: remove the stid on listen create failure

commit 8b1bbf36b7452c4acb20e91948eaa5e225ea6978 upstream.

If a listen create fails, then the server tid (stid) is incorrectly left
in the stid idr table, which can cause a touch-after-free if the stid
is looked up and the already freed endpoint is touched.  So make sure
and remove it in the error path.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>