fsnotify: fanotify -- Fix object read procedure

I occasionally read FanotifyMarkEntry object as InotifyWdEntry
in collect_one_fanotify_mark, this didn't trigger a bug in test
since the events are still occured (and before protobuf file
refine the formats were close to each other), which means
the fanotify00 test-case need to be updated (which is addressed
in further patch).

And don't forget to init fields.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>