FROMGIT: f2fs: remove unnecessary block size check in init_f2fs_fs()

After commit d7e9a903 ("f2fs: Support Block Size == Page Size"),
F2FS_BLKSIZE equals to PAGE_SIZE, remove unnecessary check condition.

Change-Id: I1ef7d5a7f94423988042a3ce629b2b00396238bd
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
(cherry picked from commit 06b206d9
https://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs.git dev)