livepatch/ppc64: Fix the stack check for exception frames

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5CJ7X



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For exception frames, we need to check NIP in addition to PC. When a
task is interrupted, NIP is the interrupt return address. The function
where the NIP is located is also on the stack.

Fixes: ec2244b5 ("livepatch/ppc64: only check stack top")
Fixes: 2a7c3db6 ("livepatch/powerpc64: Add arch_klp_module_check_calltrace")
Signed-off-by: Li Huafei <lihuafei1@huawei.com>
Reviewed-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>