monclient: use cur_con throughout
monclient: use cur_con throughout

We choose a monitor and open a connection in exactly two places.  Use
cur_con and cur_con->get_peer_addr() everywhere else.

Simplify and clean up handle_monmap a bit.

Also add an assert to catch #1534.

Signed-off-by: Sage Weil <6dd34506bbd5e58221bbb3e4732d97c91f02277b@newdream.net>

ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph