Updated 7 ansible-lint issues in the ceph-mon, ceph-osd, and ceph-rgw roles

Updated 7 ansible-lint issues in the ceph-mon, ceph-osd, and ceph-rgw roles

The following lint issues have been resolved:

[301] Commands should not change things if nothing needs doing
/home/travis/build/ceph/ceph-ansible/roles/ceph-mon/tasks/ceph_keys.yml:2

[305] Use shell only when shell functionality is required
/home/travis/build/ceph/ceph-ansible/roles/ceph-osd/tasks/start_osds.yml:47

[301] Commands should not change things if nothing needs doing
/home/travis/build/ceph/ceph-ansible/roles/ceph-rgw/tasks/multisite/destroy.yml:2

[301] Commands should not change things if nothing needs doing
/home/travis/build/ceph/ceph-ansible/roles/ceph-rgw/tasks/multisite/destroy.yml:7

[301] Commands should not change things if nothing needs doing
/home/travis/build/ceph/ceph-ansible/roles/ceph-rgw/tasks/multisite/destroy.yml:14

[301] Commands should not change things if nothing needs doing
/home/travis/build/ceph/ceph-ansible/roles/ceph-rgw/tasks/multisite/destroy.yml:19

[301] Commands should not change things if nothing needs doing
/home/travis/build/ceph/ceph-ansible/roles/ceph-rgw/tasks/multisite/destroy.yml:24

Signed-off-by: Kevin Coakley <kcoakley@sdsc.edu>