bpf: net: Change do_ipv6_setsockopt() to use the sockopt's lock_sock() and capable()

Similar to the earlier patch that avoids sk_setsockopt() from
taking sk lock and doing capable test when called by bpf.  This patch
changes do_ipv6_setsockopt() to use the sockopt_{lock,release}_sock()
and sockopt_[ns_]capable().

Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061744.4176893-1-kafai@fb.com


Signed-off-by: Alexei Starovoitov <ast@kernel.org>