fix more compile warnings

N/A

Change-Id: I5b6f9c70aea7d3f3489328834fed323d41106d9f
Signed-off-by: liuhuahang <liuhuahang@zerus.co>
Merge pull request #272 from project-zerus/patch-1

fix more compile warnings
fix asan check

Summary:
PlainTable takes reference instead of a copy. Keep a copy in the test
code

Test Plan: make asan_check

Reviewers: sdong, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22899
fixed memory leak in unit test DBIteratorBoundTest

Summary: fixed memory leak in unit test DBIteratorBoundTest

Test Plan: ran valgrind test on my unit test

Reviewers: sdong

Differential Revision: https://reviews.facebook.net/D22911