syscalls/inotify: Test generation of overflow events

Test whether overflow event is properly generated when we don't read
inotify descriptor and generate enough events.

Signed-off-by: Jan Kara <jack@suse.cz>
syscalls/fanotify: Test generation of overflow events

Test whether overflow event is properly generated when we don't read
fanotify descriptor and generate enough events.

Signed-off-by: Jan Kara <jack@suse.cz>