perf kcore_copy: Do not check /proc/modules is unchanged

stable inclusion
from stable-v5.10.146
commit c9906216068842693f44aa55b8721a1b84c5fa82
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6D0VX

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c9906216068842693f44aa55b8721a1b84c5fa82



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

[ Upstream commit 5b427df2 ]

/proc/kallsyms and /proc/modules are compared before and after the copy
in order to ensure no changes during the copy.

However /proc/modules also might change due to reference counts changing
even though that does not make any difference.

Any modules loaded or unloaded should be visible in changes to kallsyms,
so it is not necessary to check /proc/modules also anyway.

Remove the comparison checking that /proc/modules is unchanged.

Fixes: fc1b691d ("perf buildid-cache: Add ability to add kcore to the cache")
Reported-by: Daniel Dao <dqminh@cloudflare.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Daniel Dao <dqminh@cloudflare.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20220914122429.8770-1-adrian.hunter@intel.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>
Reviewed-by: Zheng Zengkai <zhengzengkai@huawei.com>