cmd-buildextend-live: update EFI/{distro}/grub.cfg to `EFI/centos/

grub.cfg` for scos

Fix openshift/os#954

src/cmd-buildextend-live

@@ -71,6 +71,16 @@ if base_name == "rhcos" and args.fast:
 currently only available for FCOS")
     sys.exit(1)
 
+# scos: rename EFI/{distro} to EFI/centos
+# https://github.com/openshift/os/issues/954
+if base_name == "scos":
+    grubfilepath = ensure_glob(os.path.join(srcdir_prefix, 'EFI/*/grub.cfg'))
+    if len(grubfilepath) != 1:
+        raise Exception(f'Found != 1 grub.cfg files: {grubfilepath}')
+    # src/config/live/EFI/{redhat -> centos}
+    efipath = os.path.dirname(grubfilepath[0])
+    os.rename(efipath, os.path.dirname(efipath) + "/centos/")
+
 # used to lock
 build_semaphore = os.path.join(buildmeta.build_dir, ".live.building")
 if os.path.exists(build_semaphore):