ix(4): Sanitize negative error codes

[pawel.sobczyk_intel.com]

Summary

Due to development history FreeBSD driver error codes are reported the same way
as in Linux (as negatives) which is inconsistent with FreeBSD standard. It may
cause unexpected behavior when driver errors are interpreted by a kernel
as syscall handler return values.
This patch converts error codes from negative to positive values for
NVM access functions.

Signed-off-by: Pawel Sobczyk <[e-mail]>

[mateusz.moga_intel.com]

Val Approved

[kbowling]

Take a look at sys/dev/ice/ice_lib.c ice_handle_nvm_access_ioctl(), I think it is a lot safer way to handle this

[erj]

In D57642#1348825, @kbowling wrote:

Take a look at sys/dev/ice/ice_lib.c ice_handle_nvm_access_ioctl(), I think it is a lot safer way to handle this

Yeah; this approach is still returning the internal ixgbe error codes which could potentially be misinterpreted regardless of whether they're positive or negative. The ice approach converts them to standard FreeBSD error codes that the kernel would expect to get out of an ioctl.

[milosz.linkiewicz_intel.com]

This comment was removed by milosz.linkiewicz_intel.com.