f2fs: check range before defragment

This patch checks the parameter range passed by ioctl to void that range
exceeds the max_file_blocks limit.

Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>