livepatch/x86_64: Fix the deadlock when insmoding livepatch kernel module

hulk inclusion
category: bugfix
bugzilla: 51843
CVE: NA

---------------------------

In function klp_init_patch, a text_mutex lock is used when
doing jump_label_apply_nops. However, the jump_label_register
in which a text_mutex lock is used is done before the original
text_mutex lock released. Thus, an AA deadlock is occured.

In this commit, we do jump_label_register after the original
text_mutex lock is released to avoid this AA deadlock.

Signed-off-by: Zhao Xuehui <zhaoxuehui1@huawei.com>
Reviewed-by: Kuohai Xu <xukuohai@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>