xerrors: use any [generated]

[git-generate]
gofmt -r 'interface{} -> any' -w .

Change-Id: I2ea2c800cd1485d57535f3b1446be728e8f5c2dd
Reviewed-on: https://go-review.googlesource.com/c/xerrors/+/610076
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
7 files changed