ceph: simplify apt-key management
ceph: simplify apt-key management

Run apt-key as root. No need to initialize ubuntu user's gpg.  Fix
whitespace.

Signed-off-by: Sage Weil <6dd34506bbd5e58221bbb3e4732d97c91f02277b@inktank.com>

caibo2014/teuthology,ceph/teuthology,michaelsevilla/teuthology,ivotron/teuthology,t-miyamae/teuthology,yghannam/teuthology,robbat2/teuthology,SUSE/teuthology,tchaikov/teuthology,dmick/teuthology,ivotron/teuthology,dmick/teuthology,t-miyamae/teuthology,robbat2/teuthology,zhouyuan/teuthology,dreamhost/teuthology,dmick/teuthology,tchaikov/teuthology,SUSE/teuthology,ktdreyer/teuthology,michaelsevilla/teuthology,ceph/teuthology,yghannam/teuthology,zhouyuan/teuthology,ktdreyer/teuthology,caibo2014/teuthology,SUSE/teuthology,dreamhost/teuthology