Summary:
Previous code had two bugs:
* didn't initialize the table_magic_number_ explicitly -- as a
result a random junk number is stored for table_magic_number_, making
HasInitializedMagicNumber() always return true.
* if condition is inconrrect in set_table_magic_number(), and the return value is not checked.
I replace if-else by a stronger requirement enforced by assert().
Test Plan:
Previous sst_dump failed to work.
After the fix, things back to normal.
Reviewers: yhchiang
CC: haobo, sdong, igor, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D17055
69f6cf431d