vendor: fix docker/docker vendoring (update to 9f28837c1d93

commit c41b006be1 updated the version of
docker/docker in go.mod, but possibly overlooked that there was still a
replace rule present. As a result the version was not actually updated.

This patch removes the replace rule, updating docker/docker to 9f28837c1d93

full diff: 4634ce647c...9f28837c1d

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

vendor/github.com/moby/sys/mount/unmount_unix.go

@@ -0,0 +1,22 @@
+// +build !windows
+
+package mount
+
+import "golang.org/x/sys/unix"
+
+func unmount(target string, flags int) error {
+	err := unix.Unmount(target, flags)
+	if err == nil || err == unix.EINVAL {
+		// Ignore "not mounted" error here. Note the same error
+		// can be returned if flags are invalid, so this code
+		// assumes that the flags value is always correct.
+		return nil
+	}
+
+	return &mountError{
+		op:     "umount",
+		target: target,
+		flags:  uintptr(flags),
+		err:    err,
+	}
+}