Update golang.org/x/sys to 95c6576299259db960f6c5b9b69ea52422860fce in
order to get the unix.Utsname with byte array instead of int8/uint8
members.
This allows to use simple byte slice to string conversions instead of
using charsToString or its open-coded version.
Also see golang/go#20753 for details.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>