criu --help: rectify --ext-unix-sk

* add missing space between option and the argument
* mark argument as optional
* fix English
* obey 80 columns width

Was:
  -x|--ext-unix-skinode,..      allow external unix connections (optionally can be assign socket's inode that allows one-sided dump)

Now:
  -x|--ext-unix-sk [inode,...]
                        allow external unix connections (optional arguments
                        are socketpair inode(s) that allow one-sided dump)
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

@@ -828,7 +828,9 @@ usage:
 "  --freeze-cgroup       use cgroup freezer to collect processes\n"
 "\n"
 "* Special resources support:\n"
-"  -x|--" USK_EXT_PARAM "inode,.." "      allow external unix connections (optionally can be assign socket's inode that allows one-sided dump)\n"
+"  -x|--" USK_EXT_PARAM " [inode,...]\n"
+"                        allow external unix connections (optional arguments\n"
+"                        are socketpair inode(s) that allow one-sided dump)\n"
 "     --" SK_EST_PARAM "  checkpoint/restore established TCP connections\n"
 "     --" SK_INFLIGHT_PARAM "   this option skips in-flight TCP connections.\n"
 "                        if TCP connections are found which are not yet completely\n"