fscrypt: Use constant protector name

Use constant protector name 'ceph-csi' instead of constant prefix
concatenated with the volume ID. When cloning volumes the ID changes
and fscrypt protected directories become inunlockable due to the
protector name change

Signed-off-by: Marcel Lauhoff <marcel.lauhoff@suse.com>

internal/util/fscrypt/fscrypt.go

@@ -383,7 +383,7 @@ func Unlock(
 			metadataDirExists, kernelPolicyExists)
 	}
 
-	protectorName := fmt.Sprintf("%s-%s", FscryptProtectorPrefix, volEncryption.GetID())
+	protectorName := FscryptProtectorPrefix
 
 	switch volEncryption.KMS.RequiresDEKStore() {
 	case kms.DEKStoreMetadata: