IfAPI: hide struct ifaddr from if_foreach_addr_type() callbacks

[glebius]

Summary

struct ifaddr is an internal structure, just like ifnet. The IfAPI
should keep it opaque from drivers.

[kgalazka]

LGTM but let me ask @bartosz.sobczak_intel.com to take a look at irdma changes.

[glebius]

In D48054#1101622, @krzysztof.galazka_intel.com wrote:

LGTM but let me ask @bartosz.sobczak_intel.com to take a look at irdma changes.

Thanks! This is the part I can't test, so will really appreciate.

[bartosz.sobczak_intel.com]

In D48054#1101719, @glebius wrote:

In D48054#1101622, @krzysztof.galazka_intel.com wrote:

LGTM but let me ask @bartosz.sobczak_intel.com to take a look at irdma changes.

Thanks! This is the part I can't test, so will really appreciate.

Visually looks fine. let us run a test or two.