launch.py: Fix inventory list

This was introduced with Ia67e65d25a1d961b619aa445303015fd577dee57

Passing "-i file1,file2,file.." makes Ansible think that the inventory
argument is a list of hostnames.  Separate out the "-i" flags so it
reads each file as desired.

Change-Id: I92c9a74de6552968da6c919074d84f2911faf4d4

launch/launch-node.py

@@ -170,20 +170,19 @@ def bootstrap_server(server, key, name, volume_device, keep,
         t.daemon = True
         t.start()
 
-        inventory_list = ','.join([
+        inventory_list = (
             jobdir.inventory_root,
             '/opt/system-config/inventory/openstack.yaml',
             '/opt/system-config/inventory/groups.yaml',
             '/opt/system-config/inventory/emergency.yaml',
-        ])
-        ansible_cmd = [
-            'ansible-playbook',
-            '--flush-cache',
-            '-i', inventory_list, '-l', name,
-            '--private-key={key}'.format(key=jobdir.key),
-            "--ssh-common-args='-o StrictHostKeyChecking=no'",
-            '-e', 'target={name}'.format(name=name),
-        ]
+        )
+        inventory_cmds = [v for e in inventory_list for v in ('-i', e)]
+        ansible_cmd = ['ansible-playbook', '--flush-cache' ] + \
+            inventory_cmds + \
+            ['-l', name,
+             '--private-key={key}'.format(key=jobdir.key),
+             "--ssh-common-args='-o StrictHostKeyChecking=no'",
+             '-e', 'target={name}'.format(name=name)]
 
         # Run the base playbook limited to just this server we just created
         for playbook in [