sm-notify: Avoid extra rpcbind queries

sm-notify: Avoid extra rpcbind queries

The logic in notify_host() watches the host->retries counter to see if
progress is not being made.  If progress stalls, notify_host() tries
another IP address.  This means sm-notify will generate a fresh
rpcbind query.

After an RPC succeeds, be sure to reset host->retries so sm-notify
doesn't start walking down the host's addrinfo list when we _are_
making progress.  In the common case, if the host responds, we avoid
extra rpcbind queries and send all requests for the host to the same
IP address.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Steve Dickson <steved@redhat.com>