ksmbd: fix use-after-free in ksmbd_tree_connect_put under concurrency
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix use-after-free in ksmbd_tree_connect_put under concurrency
Under high concurrency, A tree-connection object (tcon) is freed on
a disconnect path while another path still holds a reference and later
executes *_put()/write on it.