Enable show-partition without -d.

pym/cl_install_cmd.py

@@ -257,6 +257,7 @@ class install_cmd(share_cmd):
                                        example="default:192.168.1.1"))
         if not (values.install or values.uninstall or values.live):
             if values.v is False and \
+               not values.p and \
                values.d is None and \
                not self.logicObj.clVars.Get('os_install_dev_from'):
                 self.optobj.error(_("need specify disk by '-d' option"))