[rt] net: ensure proper lock order when acquiring raw_v6_hashinfo lock in raw_seq_start()

Bugzilla: https://bugzilla.redhat.com/1984293
Upstream Status: RHEL only.

Except by raw_seq_start(), raw_v6_hashinfo lock is always acquired with
bottom halves disabled. Ensure raw_seq_start() behaves the same way.

Signed-off-by: Luis Claudio R. Goncalves lgoncalv@redhat.com