Remove -D_FILE_OFFSET_BITS=64 on host builds

This prevents us from using glibc's <fts.h> because of
https://sourceware.org/bugzilla/show_bug.cgi?id=11460,
and we now only support 64-bit hosts.

Bug: 139544611
Test: Treehugger
Change-Id: Iaacc9ea17473201bf3d701e82081264921062d5e
1 file changed