dissect-image: lazily deactivate decrypted DM volumes

The DM block device may be still used by other processes.

src/shared/dissect-image.c

@@ -1567,7 +1567,8 @@ DecryptedImage* decrypted_image_unref(DecryptedImage* d) {
                 DecryptedPartition *p = d->decrypted + i;
 
                 if (p->device && p->name && !p->relinquished) {
-                        r = sym_crypt_deactivate_by_name(p->device, p->name, 0);
+                        /* Let's deactivate lazily, as the dm volume may be already/still used by other processes. */
+                        r = sym_crypt_deactivate_by_name(p->device, p->name, CRYPT_DEACTIVATE_DEFERRED);
                         if (r < 0)
                                 log_debug_errno(r, "Failed to deactivate encrypted partition %s", p->name);
                 }