f2fs: remove redundant judgement condition in available_free_memory

In available_free_memory, there are two same judgement conditions which
is used for checking NAT excess, remove one of them.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
1 file changed