upstart: Make ceph-osd always set the crush location.

upstart: Make ceph-osd always set the crush location.

This used to be conditional on config having osd_crush_location set,
but with that, minimal configuration left the OSD completely out of
the crush map, and prevented the OSD from starting properly.

Note: Ceph does not currently let this mechanism automatically move
hosts to another location in the CRUSH hierarchy. This means if you
let this run with defaults, setting osd_crush_location later will not
take effect. Set up your config file (or Chef environment) fully
before starting the OSDs the first time.

Signed-off-by: Tommi Virtanen <tv@inktank.com>