storage: rbd: actually index the array when iterating over it

https://bugzilla.redhat.com/show_bug.cgi?id=1729292

Fixes: 3aa190f2Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

src/storage/storage_backend_rbd.c

@@ -637,7 +637,7 @@ virStorageBackendRBDGetVolNames(virStorageBackendRBDStatePtr ptr)
     nnames = nimages;
 
     for (i = 0; i < nimages; i++)
-        VIR_STEAL_PTR(names[i], images->name);
+        VIR_STEAL_PTR(names[i], images[i]->name);
 
     return names;