Do not use -DUSE_*MALLOC for host build

When we use ninja and switch a lunch target to another, they
may cause unnecessary rebuild because ninja detects command
line changes. They are used in #ifdef HAVE_ANDROID_OS so there
should be no semantics changes.

Change-Id: I629c94c872c8fc8ba4b4c59b565338e14570c3fe
1 file changed