crtools: restore flock&posix file locks

According to the file lock information from the image, we recall
flock or fcntl with proper parameters, so we can rehold the file
locks as we were dumped.
We only support flock and posix file locks so far.

Changelog since the initial version:
a. Use prepare_file_locks instead of restore function directly.
b. Fix some bugs.

Originally-signed-off-by: Zheng Gu <cengku.gu@huawei.com>
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>