checkpatch: exclude lib/posix/*.c from negative errno rule

The `USE_NEGATIVE_ERRNO` rule consistently generates false
positives when working with certain areas of POSIX.

It makes sense to disable this check for the POSIX API
rather than requiring merge superpowers constantly. That
way, we can merge as per usual after sufficient approvals
rather than waiting for someone with merge superpowers to
override / manually merge.

Signed-off-by: Christopher Friedt <cfriedt@meta.com>
1 file changed