f2fs: remove unneeded write checkpoint in recover_fsync_data

Previously, recover_fsync_data still to write checkpoint when there is
nothing to recover with normal umount image.
It may reduce mount performance and flash memory lifetime, so let's remove
it.

Signed-off-by: Tan Shu <shu.tan@samsung.com>
Signed-off-by: Yu Chao <chao2.yu@samsung.com>
Reviewed-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>