f2fs: fix memory leak of percpu counter in fill_super()

In fill_super -> init_percpu_info, we should destroy percpu counter
in error path, otherwise memory allcoated for percpu counter will
leak.

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