tracing/osnoise: Fix missed cpus_read_unlock() in start_per_cpu_kthreads()

mainline inclusion
from mainline-v5.15-rc1
commit 4b6b08f2
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4G64B
CVE: NA

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

When start_kthread() return error, the cpus_read_unlock() need
to be called.

Link: https://lkml.kernel.org/r/20210831022919.27630-1-qiang.zhang@windriver.com



Cc: <stable@vger.kernel.org>
Fixes: c8895e27 ("trace/osnoise: Support hotplug operations")
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Qiang.Zhang <qiang.zhang@windriver.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Wang ShaoBo <bobo.shaobowang@huawei.com>
Acked-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>