Add new internal state marking resilience type as not set.

lib/luks2/luks2_internal.h

@@ -139,7 +139,8 @@ typedef struct  {
 } keyslot_handler;
 
 struct reenc_protection {
-	enum { REENC_PROTECTION_NONE = 0, /* none should be 0 always */
+	enum { REENC_PROTECTION_NOT_SET = 0,
+	       REENC_PROTECTION_NONE,
 	       REENC_PROTECTION_CHECKSUM,
 	       REENC_PROTECTION_JOURNAL,
 	       REENC_PROTECTION_DATASHIFT } type;

lib/luks2/luks2_reencrypt.c

@@ -1229,6 +1229,9 @@ static int reencrypt_hotzone_protect_ready(struct crypt_device *cd,
 {
 	assert(rp);
 
+	if (rp->type == REENC_PROTECTION_NOT_SET)
+		return -EINVAL;
+
 	if (rp->type != REENC_PROTECTION_CHECKSUM)
 		return 0;