auth: Do not print error message for SSH_AGAIN

In non-blocking mode, it is expected SSH_AGAIN to be returned many
times.  Do not flood the log with error messages.

Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>

src/auth.c

@@ -69,7 +69,7 @@ static int ssh_userauth_request_service(ssh_session session) {
     int rc;
 
     rc = ssh_service_request(session, "ssh-userauth");
-    if (rc != SSH_OK) {
+    if ((rc != SSH_OK) && (rc != SSH_AGAIN)) {
         SSH_LOG(SSH_LOG_WARN,
                 "Failed to request \"ssh-userauth\" service");
     }