perf header: remove unecessary core id test

It is possible for systems to have a greater socket id number than the
number of cpus present on a machine, so this test is obselete and should
be removed.

Signed-off-by: Anubhav Shelat <ashelat@redhat.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250618142921.4053400-2-ashelat@redhat.com


Signed-off-by: Namhyung Kim <namhyung@kernel.org>