f2fs: unify string length declarations and usage

This patch is intended to unify string length declarations and usage.
There are number of calls to strlen which return size_t object.
The size of this object depends on compiler if it will be bigger,
equal or even smaller than an unsigned int

Signed-off-by: Leon Romanovsky <leon@leon.nu>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

diff --cc fs/f2fs/dir.c
Simple merge

diff --cc fs/f2fs/f2fs.h
Simple merge

diff --cc fs/f2fs/hash.c
Simple merge

diff --cc fs/f2fs/namei.c
Simple merge

diff --cc fs/f2fs/xattr.c
Simple merge