ksmbd: fix memory leak in parse_lease_state()

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix memory leak in parse_lease_state() The previous patch that added bounds check for create lease context introduced a memory leak. When the bounds check fails, the function returns NULL without freeing the previously allocated lease_ctx_info structure. This patch fixes the issue by adding kfree(lreq) before returning NULL in both boundary check cases.