When we compare sets in cg_set_compare() we presume that controller
names are properly sorted but because of use of strcmp(cc->path, path)
it's not true. In particular in case if there are two same sets which
differ in paths only

(00.126812) cg:  `- New css ID 2
(00.127051) cg:     `- [memory] -> [/vz-1]
(00.127079) cg:     `- [name=systemd] -> [/vz-1]
(00.127108) cg:     `- [net_cls] -> [/vz-1]

(00.239829) cg:  `- New css ID 3
(00.240067) cg:     `- [memory] -> [/vz-1]
(00.240096) cg:     `- [net_cls] -> [/vz-1]
(00.240154) cg:     `- [name=systemd] -> [/vz-1/system.slice/dbus.service]

we currently refuse to dump such configuretion. Thus remove
path comparision from the first place.

CC: Tycho Andersen <tycho.andersen@canonical.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Tycho Andersen <tycho.andersen@canonical.com>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>