Simplify Utsname string conversion

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>

vendor/golang.org/x/sys/unix/syscall_darwin.go

@@ -54,7 +54,7 @@ func nametomib(name string) (mib []_C_int, err error) {
 
 	// NOTE(rsc): It seems strange to set the buffer to have
 	// size CTL_MAXNAME+2 but use only CTL_MAXNAME
-	// as the size.  I don't know why the +2 is here, but the
+	// as the size. I don't know why the +2 is here, but the
 	// kernel uses +2 for its own implementation of this function.
 	// I am scared that if we don't include the +2 here, the kernel
 	// will silently write 2 words farther than we specify
@@ -377,7 +377,6 @@ func IoctlGetTermios(fd int, req uint) (*Termios, error) {
 // Searchfs
 // Delete
 // Copyfile
-// Poll
 // Watchevent
 // Waitevent
 // Modwatch