linux-user: fix sockaddr_in6 endianness

linux-user: fix sockaddr_in6 endianness

The sin6_scope_id field uses the host byte order, so there is a
conversion to be made when host and target endianness differ.

Signed-off-by: Mathis Marion <mathis.marion@silabs.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230307154256.101528-2-Mathis.Marion@silabs.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
(cherry picked from commit 44cf6731d6b9a48bcd57392e8cd6f0f712aaa677)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>