netpoll: Remove unused fields from inet_addr union

Clean up the inet_addr union by removing unused fields that are
redundant with existing members:

This simplifies the union structure while maintaining all necessary
functionality for both IPv4 and IPv6 address handling.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250723-netconsole_ref-v3-1-8be9b24e4a99@debian.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>