librados: rectify the guard in RadosClient::wait_for_osdmap().

librados: rectify the guard in RadosClient::wait_for_osdmap().

RadosClient::wait_for_osdmap() did not signalize lack of connection
via -ENOTCONN error code when the Objecter instance was allocated.
The proper way is to check the connection state explicitly.

Signed-off-by: Radoslaw Zarzynski <rzarzynski@mirantis.com>
(cherry picked from commit 34473f78f101d87d2606e0e7112682a47ff24830)

Conflicts:
	src/librados/RadosClient.cc
        the modified guard was not present: add the new guard instead
        of modifying it