fsnotify: parse_fdinfo_pid_s() returns allocated object for inotify wd (v2)

We are going to collect all objects in a list and write them into
the inotify image. The inotify wd image will be depricated.

v2: cb() must always free an entry
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>