vendor: cadvisor v0.39.0

Main upgrades:
- github.com/opencontainers/runc v1.0.0-rc93
- github.com/containerd/containerd v1.4.4
- github.com/docker/docker v20.10.2
- github.com/mrunalp/fileutils v0.5.0
- github.com/opencontainers/selinux v1.8.0
- github.com/cilium/ebpf v0.2.0

vendor/github.com/opencontainers/selinux/pkg/pwalk/pwalk.go

@@ -20,17 +20,16 @@ type WalkFunc = filepath.WalkFunc
 //
 // Note that this implementation only supports primitive error handling:
 //
-// * no errors are ever passed to WalkFn
+// - no errors are ever passed to WalkFn;
 //
-// * once a walkFn returns any error, all further processing stops
-//   and the error is returned to the caller of Walk;
+// - once a walkFn returns any error, all further processing stops
+// and the error is returned to the caller of Walk;
 //
-// * filepath.SkipDir is not supported;
-//
-// * if more than one walkFn instance will return an error, only one
-//   of such errors will be propagated and returned by Walk, others
-//   will be silently discarded.
+// - filepath.SkipDir is not supported;
 //
+// - if more than one walkFn instance will return an error, only one
+// of such errors will be propagated and returned by Walk, others
+// will be silently discarded.
 func Walk(root string, walkFn WalkFunc) error {
 	return WalkN(root, walkFn, runtime.NumCPU()*2)
 }
@@ -38,6 +37,8 @@ func Walk(root string, walkFn WalkFunc) error {
 // WalkN is a wrapper for filepath.Walk which can call multiple walkFn
 // in parallel, allowing to handle each item concurrently. A maximum of
 // num walkFn will be called at any one time.
+//
+// Please see Walk documentation for caveats of using this function.
 func WalkN(root string, walkFn WalkFunc, num int) error {
 	// make sure limit is sensible
 	if num < 1 {