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

grub.cfg` for scos

Fix openshift/os#954

src/cmd-buildextend-live

@@ -524,6 +524,15 @@ def generate_iso():
             if len(vendor_ids) != 1:
                 raise Exception(f"did not find exactly one EFI vendor ID: {vendor_ids}")
 
+            # scos: rename EFI/{distro} to EFI/centos
+            # https://github.com/openshift/os/issues/954
+            if base_name == "scos":
+                grubfilepath = ensure_glob(os.path.join(tmpdir, 'live/EFI/*/grub.cfg'))
+                if len(grubfilepath) != 1:
+                    raise Exception(f'Found != 1 grub.cfg files: {grubfilepath}')
+                srcpath = os.path.dirname(grubfilepath[0])
+                os.renames(grubfilepath[0], os.path.join(os.path.dirname(srcpath), vendor_ids[0], "grub.cfg"))
+
             # Delete fallback and its CSV file.  Its purpose is to create
             # EFI boot variables, which we don't want when booting from
             # removable media.