CVE-2022-50620 f2fs: fix to invalidate dcc->f2fs_issue_discard in error path

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to invalidate dcc-f2fsissuediscard in error path Syzbot reports a NULL pointer dereference issue as below: refcountadd include/linux/refcount.h:193 inline refcountinc include/linux/refcount.h:250 inline refcountinc...