CVE-2022-50148 kernfs: fix potential NULL dereference in __kernfs_remove

In the Linux kernel, the following vulnerability has been resolved: kernfs: fix potential NULL dereference in kernfsremove When lockdep is enabled, lockdepassertheldwrite would cause potential NULL pointer dereference. Fix the following smatch warnings: fs/kernfs/dir.c:1353 kernfsremove warn:...