linux-user: call fd_trans_target_to_host_data() for write()

linux-user: call fd_trans_target_to_host_data() for write()

As for sendmsg() or sendto(), we must call the target to
host data translator if it is defined. This is needed for
eventfd(): the write() syscall allows to add a value to
the internal counter, and so, it must be byte-swapped to
the host order.

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>