ksmbd: fix use-after-free in smb_lazy_parent_lease_break_close()

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: fix use-after-free in smb_lazy_parent_lease_break_close()

opinfo pointer obtained via rcu_dereference(fp->f_opinfo) is being

accessed after rcu_read_unlock() has been called. This creates a

race condition where the memory could be freed by a concurrent

writer between the unlock and the subsequent pointer dereferences

(opinfo->is_lease, etc.), leading to a use-after-free.