net: remove SOCK_SUPPORT_ZC from sockmap

sockmap replaces ->sk_prot with its own callbacks, we should remove
SOCK_SUPPORT_ZC as the new proto doesn't support msghdr::ubuf_info.

Cc: <stable@vger.kernel.org> # 6.0
Reported-by: Jakub Kicinski <kuba@kernel.org>
Fixes: e993ffe3 ("net: flag sockets supporting msghdr originated zerocopy")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>