linux-user: translate the result of getsockopt SO_TYPE

linux-user: translate the result of getsockopt SO_TYPE

QEMU previously passed the result of the host syscall directly to the
target program. This is a problem if the host & target have different
representations of socket types, as is the case when running a MIPS
target program on an x86 host. Introduce a host_to_target_sock_type
helper function mirroring the existing target_to_host_sock_type, and
call it to translate the value provided by getsockopt when called for
the SO_TYPE option.

Signed-off-by: Paul Burton <paul@archlinuxmips.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>