vm: fix extraneous parentheses warnings

Summary:
This warning is treated as an error with clang and -Werror.
Fixes the following:
  equality comparison with extraneous parentheses

Test Plan: verify

Reviewers: randall.rushing, synergy

Reviewed By: synergy

Differential Revision: http://review.codefirex.com/D598

Change-Id: I3ff97ad2e4c63abffdd921c7910ba94c50a33a34
Signed-off-by: DHOMD <DHO@dho.im>
vm: fix C++11 build after stdint update

If __STDINT_LIMITS is defined, SIZE_MAX
is defined twice.

Change-Id: I8d35157e3157ccd6fffc9c980557e0986859d20e
Signed-off-by: DHOMD <DHO@dho.im>