Fix duplicate radosgw package resource

The ceph::rgw defined resource type may be used multiple times, so
we should make sure the package resource does not cause conflict.

Change-Id: Iaf6cc6b8bc7b2318cae91b3ef4f9fa2859d13c69
Signed-off-by: Takashi Kajinami <kajinamit@oss.nttdata.com>

manifests/rgw.pp

@@ -163,10 +163,10 @@ define ceph::rgw (
     }
   }
 
-  package { $pkg_radosgw_real:
+  stdlib::ensure_packages( $pkg_radosgw_real, {
     ensure => installed,
     tag    => 'ceph',
-  }
+  })
 
   # Data directory for radosgw
   file { $rgw_data: