Fix authorized_keys generation at cluster init

Copy pub_key in authorized_keys.

Signed-off-by: Luca Bigliardi <shammash@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

lib/bootstrap.py

@@ -63,7 +63,7 @@ def _InitSSHSetup():
     raise errors.OpExecError("Could not generate ssh keypair, error %s" %
                              result.output)
 
-  utils.AddAuthorizedKey(auth_keys, utils.ReadFile(auth_keys))
+  utils.AddAuthorizedKey(auth_keys, utils.ReadFile(pub_key))
 
 
 def _GenerateSelfSignedSslCert(file_name, validity=(365 * 5)):