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

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

[ Upstream commit 053f6041cf6cec7bea4ab9e93518d3a892463f3f ]

/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: 997b47be4455bff1 ("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>