genl: Restore handling of errors

Error handling for genl was broken.  Fix that.

Also while here, rename netlink_parse_ext_ack() to
netlink_parse_ext_ack_error() so as to better convey it intended
purpose.  Drop certain checks from netlink_parse_ext_ack_error() since
they were redundant.

Fixes: 64238ccf471a ("genl,netlink: Move extended ACK code to netlink-private")
3 files changed