fsnotify: Proceed dumping even if queue has data

It turns out that we can't be too strict about
queued events -- criu itself generates a number
of them and there is no clear way yet how to resolve
this situation. So defer "strict" mode for now
but print a warning.

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