Clean vendor dependencies

vendor/github.com/containerd/continuity/fs/time.go

@@ -1,29 +0,0 @@
-/*
-   Copyright The containerd Authors.
-
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
-
-       http://www.apache.org/licenses/LICENSE-2.0
-
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.
-*/
-
-package fs
-
-import "time"
-
-// Gnu tar and the go tar writer don't have sub-second mtime
-// precision, which is problematic when we apply changes via tar
-// files, we handle this by comparing for exact times, *or* same
-// second count and either a or b having exactly 0 nanoseconds
-func sameFsTime(a, b time.Time) bool {
-	return a == b ||
-		(a.Unix() == b.Unix() &&
-			(a.Nanosecond() == 0 || b.Nanosecond() == 0))
-}