xtensa: patch_text: Fixup last cpu should be master

stable inclusion
from stable-v5.10.113
commit f399ab11dd6cc0a6927029371fbe2ec027181598
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5ISAH

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f399ab11dd6cc0a6927029371fbe2ec027181598



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

commit ee69d4be upstream.

These patch_text implementations are using stop_machine_cpuslocked
infrastructure with atomic cpu_count. The original idea: When the
master CPU patch_text, the others should wait for it. But current
implementation is using the first CPU as master, which couldn't
guarantee the remaining CPUs are waiting. This patch changes the
last CPU as the master to solve the potential risk.

Fixes: 64711f9a ("xtensa: implement jump_label support")
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: <stable@vger.kernel.org>
Message-Id: <20220407073323.743224-4-guoren@kernel.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Acked-by: Xie XiuQi <xiexiuqi@huawei.com>