fixed bug from prev update

Signed-off-by: Brian Coca <briancoca+dev@gmail.com>

library/system/lvg

@@ -210,7 +210,7 @@ def main():
                             module.fail_json(msg="Creating physical volume '%s' failed"%current_dev, rc=rc, err=err)
                     ### add PV to our VG
                     vgextend_cmd = module.get_bin_path('vgextend', True)
-                    rc,_,err = module.run_command("vgextend %s %s"%(vgextend_cmd, vg, devs_to_add_string))
+                    rc,_,err = module.run_command("%s %s %s"%(vgextend_cmd, vg, devs_to_add_string))
                     if rc == 0:
                         changed = True
                     else: