deploy: Remove checksum from generated loader entries

The actual deployment checksum shouldn't be in there, because we may
just swap bootlinks, rendering the name of the old bootloader entry
file invalid.  Thankfully nothing actually parsed the names of these
files, so let's just use the index.

src/libostree/ostree-sysroot-deploy.c

@@ -850,10 +850,9 @@ install_deployment_kernel (OstreeSysroot   *sysroot,
   bootcsumdir = ot_gfile_resolve_path_printf (bootdir, "ostree/%s-%s",
                                               osname,
                                               bootcsum);
-  bootconfpath = ot_gfile_resolve_path_printf (bootdir, "loader.%d/entries/ostree-%s-%s-%d.conf",
+  bootconfpath = ot_gfile_resolve_path_printf (bootdir, "loader.%d/entries/ostree-%s-%d.conf",
                                                new_bootversion, osname, 
-                                               ostree_deployment_get_csum (deployment),
-                                               ostree_deployment_get_bootserial (deployment));
+                                               ostree_deployment_get_index (deployment));
 
   if (!gs_file_ensure_directory (bootcsumdir, TRUE, cancellable, error))
     goto out;