Fix BlockBasedTableTest.NoopTransformSeek failure

Fix BlockBasedTableTest.NoopTransformSeek failure

Summary:
table_test is failing because we are creating a temp InternalComparator

14:27:28 [ RUN      ] BlockBasedTableTest.NoopTransformSeek
14:27:28 pure virtual method called
14:27:28 terminate called without an active exception
14:27:28 /bin/sh: line 7: 2346261 Aborted                 (core dumped) ./$t

Test Plan: make table_test -j64 && ./table_test --gtest_filter="BlockBasedTableTest.NoopTransformSeek"

Reviewers: igor, sdong, anthony, rven

Reviewed By: rven

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D52671