net/netip: fix TestInlining after CL 585057

net/netip: fix TestInlining after CL 585057

Addr.AsSlice is not inlinable on all architectures.

Fixes #67354

Change-Id: Ibaf7daa2e1188a05952f8df3c84255436b29478d
Reviewed-on: https://go-review.googlesource.com/c/go/+/585058
Auto-Submit: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Mateusz Poliwczak <mpoliwczak34@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: abner chenc <chenguoqi@loongson.cn>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: abner chenc <chenguoqi@loongson.cn>
Reviewed-by: Mauri de Souza Meneguzzo <mauri870@gmail.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>