[RFC] perf: Reconsider an error code selection in bpf_map__fprintf()

[Markus Elfring]

Hello,

A null pointer check is performed for the input parameter “map”.
It looks suspicious that the function “PTR_ERR” is applied then for
a corresponding return statement.
https://elixir.bootlin.com/linux/v6.8-rc2/source/tools/perf/util/bpf_map.c#L29
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/perf/util/bpf_map.c?h=v6.8-rc2&id=41bccc98fb7931d63d03f326a746ac4d429c1dd3#n29

This issue was detected by using the Coccinelle software.

Would any other error code determination be more appropriate here?

Regards,
Markus