f2fs_utils: enable mac build by removing dead codes

We don't need to compile some dead codes, since we start to use make_f2fs built
from external/f2fs-tools directly.

Bug: 69298953
Change-Id: If4e3babcf0b3868a3368e89787b251d305719a0f
Signed-off-by: Jaegeuk Kim <jaegeuk@google.com>
6 files changed