criu --help: rectify --empty-ns description

* Fix typos ("an user", "retore")
* Rephrase
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

criu/crtools.c

@@ -892,8 +892,8 @@ usage:
 "                            socket[inode]\n"
 "                            file[mnt_id:inode]\n"
 "  --empty-ns {net}\n"
-"                        Create a namespace, but don't restore its properies.\n"
-"                        An user will retore them from action scripts\n"
+"                        Create a namespace, but don't restore its properies\n"
+"                        (assuming it will be restored by action scripts)\n"
 "  -J|--join-ns NS:PID|NS_FILE[,EXTRA_OPTS]\n"
 "			Join exist namespace and restore process in it.\n"
 "			Namespace can be specified in pid or file path format.\n"