libcontainer: rename keyctl package to keys

This avoid the goimports tool from remove the libcontainer/keys import line due the package name is diferent from folder name

Signed-off-by: Guilherme Rezende <guilhermebr@gmail.com>

libcontainer/setns_init_linux.go

@@ -26,7 +26,7 @@ func (l *linuxSetnsInit) getSessionRingName() string {
 func (l *linuxSetnsInit) Init() error {
 	if !l.config.Config.NoNewKeyring {
 		// do not inherit the parent's session keyring
-		if _, err := keyctl.JoinSessionKeyring(l.getSessionRingName()); err != nil {
+		if _, err := keys.JoinSessionKeyring(l.getSessionRingName()); err != nil {
 			return err
 		}
 	}