init-ceph: make ulimit -n be part of daemon command

ulimit -n from 'max open files' was being set only on the machine
running /etc/init.d/ceph.  It needs to be added to the commands to
start the daemons, and run both locally and remotely.

Fixes: #3900
Signed-off-by: Dan Mick <dan.mick@inktank.com>