keyring permissions: fix PATH

PATH needs to include:
- /usr/sbin and /usr/bin
- /sbin and /bin

for running grep and groups commands.

Signed-off-by: Emilien Macchi <emilien.macchi@enovance.com>

manifests/volume/backend/rbd.pp

@@ -82,7 +82,7 @@ define cloud::volume::backend::rbd (
 
   ensure_resource ('exec','add-cinder-to-group', {
     'command' => 'usermod -a -G cephkeyring cinder',
-    'path'    => ['/usr/sbin', '/sbin'],
+    'path'    => ['/usr/sbin', '/usr/bin', '/bin', '/sbin'],
     'unless'  => 'groups cinder | grep cephkeyring'
   })