sload.f2fs: update build for android

sload.f2fs: update build for android

This patch updates sload.f2fs for android build.

- do fsck() after sload() to update quota information.
- return success, if there's no source directory

  -C fs_config

  -f source directory [path of the source directory]

  -p product out directory
    : path on fs_config file for uid/gid/mode

  -s file_contexts
    : selabel file

  -t mount point [prefix of target fs path, default:/]
     : path stored in selabel/fs_config files

  -T timestamp

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>