bpf: add missing ops lock around dev_xdp_attach_link

bpf: add missing ops lock around dev_xdp_attach_link

Syzkaller points out that create_link path doesn't grab ops lock,
add it.

Reported-by: syzbot+08936936fe8132f91f1a@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/bpf/67e6b3e8.050a0220.2f068f.0079.GAE@google.com/
Fixes: 97246d6d21c2 ("net: hold netdev instance lock during ndo_bpf")
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250331142814.1887506-1-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>