sk-inet: No need for 128 byte address

The SO_PEERNAME sockopt reports -EINVAL if the len passed is greater
than the real one, and copies part of the address otherwise. Need to
pass there "good" optlen not to get -EINVAL falsely. On the other
hand, since we only need to check for connected/not-connected it's
enough to push there 1 byte.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>