f2fs: clean up val{>>,<<}F2FS_BLKSIZE_BITS

Use F2FS_BYTES_TO_BLK(bytes) and F2FS_BLK_TO_BYTES(blk) for cleanup

Signed-off-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>