Fix 2 warning when building with GCC 5.

These caused the following warning with GCC 5:
     warning: logical not is only applied to the left hand side of
     comparison [-Wlogical-not-parentheses]
     assert(!is_compound == (cm->reference_mode == SINGLE_REFERENCE));

Change-Id: If296aabb2311ceb7d903b395c1549ef81c2cbf9b
2 files changed