build: move e2e dependencies into e2e/go.mod

Several packages are only used while running the e2e suite. These
packages are less important to update, as the they can not influence the
final executable that is part of the Ceph-CSI container-image.

By moving these dependencies out of the main Ceph-CSI go.mod, it is
easier to identify if a reported CVE affects Ceph-CSI, or only the
testing (like most of the Kubernetes CVEs).

Signed-off-by: Niels de Vos <ndevos@ibm.com>

e2e/vendor/github.com/karrick/godirwalk/nameWithNamlen.go

@@ -0,0 +1,29 @@
+// +build aix darwin dragonfly freebsd netbsd openbsd
+
+package godirwalk
+
+import (
+	"reflect"
+	"syscall"
+	"unsafe"
+)
+
+func nameFromDirent(de *syscall.Dirent) []byte {
+	// Because this GOOS' syscall.Dirent provides a Namlen field that says how
+	// long the name is, this function does not need to search for the NULL
+	// byte.
+	ml := int(de.Namlen)
+
+	// Convert syscall.Dirent.Name, which is array of int8, to []byte, by
+	// overwriting Cap, Len, and Data slice header fields to values from
+	// syscall.Dirent fields. Setting the Cap, Len, and Data field values for
+	// the slice header modifies what the slice header points to, and in this
+	// case, the name buffer.
+	var name []byte
+	sh := (*reflect.SliceHeader)(unsafe.Pointer(&name))
+	sh.Cap = ml
+	sh.Len = ml
+	sh.Data = uintptr(unsafe.Pointer(&de.Name[0]))
+
+	return name
+}