all: update to current golang.org/x/sys revision

all: update to current golang.org/x/sys revision

go get -d golang.org/x/sys@6c1b26c55098eae66ce95ab7c3712ab6cbfff2b7
go mod tidy
go mod vendor

This fixes the problem of the second return value in syscall on linux/loong64.

Change-Id: I8018ae96f4e5ca9779b2c053cdccc6b2866bf0de
Reviewed-on: https://go-review.googlesource.com/c/go/+/412274
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Bryan Mills <bcmills@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>