sst_dump: still try to print out table properties even if failing to read the file

Summary: Even if the file is corrupted, table properties are usually available to print out. Now sst_dump would just fail without printing table properties. With this patch, table properties are still try to be printed out.

Test Plan: run sst_dump against multiple scenarios

Reviewers: igor, yhchiang, ljin, haobo

Reviewed By: haobo

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D18981