Apply InfoLogLevel to the logs in table/block_based_table_reader.cc

Summary:
Apply InfoLogLevel to the logs in table/block_based_table_reader.cc

Also, add missing checks for the returned status in BlockBasedTable::Open

Test Plan: make

Reviewers: sdong, ljin, igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D28005