ssh_event_dopoll can also return SSH_AGAIN

Signed-off-by: Till Wimmer <g4-lisz@tonarchiv.ch>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>

src/poll.c

@@ -952,6 +952,7 @@ int ssh_event_add_connector(ssh_event event, ssh_connector connector){
  *                      the poll() function.
  * @returns SSH_OK      on success.
  *          SSH_ERROR   Error happened during the poll.
+ *          SSH_AGAIN   Timeout occured
  */
 int ssh_event_dopoll(ssh_event event, int timeout) {
     int rc;