linux-phytec-fsl

f2fs: introduce a new ioctl F2FS_IOC_WRITE_CHECKPOINT

This patch introduce a new ioctl for those users who want to trigger
checkpoint from userspace through ioctl.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>