bootloader/config/grub2: Handle ostree case for BLS configs

- Do not replace but append to the existing kernel command line as it is
  correct
- Do not fix the path to the kernel & initrd as those are also correct

kiwi/bootloader/config/grub2.py

@@ -319,8 +319,13 @@ def setup_disk_image_config(
         # be deleted...
         if self.xml_state.build_type.get_overlayroot_write_partition() is not False:
             self._fix_grub_root_device_reference(config_file, boot_options)
-            self._fix_grub_loader_entries_boot_cmdline()
-            self._fix_grub_loader_entries_linux_and_initrd_paths()
+            if not Defaults.is_ostree(self.root_dir):
+                self._fix_grub_loader_entries_boot_cmdline()
+                self._fix_grub_loader_entries_linux_and_initrd_paths()
+            else:
+                # In the ostree case, the BLS entries are correct, but we still
+                # need to append the additionnal kernel command line arguments
+                self.grub_loader_entries_boot_cmdline_append()
 
         if self.firmware.efi_mode() and self.early_boot_script_efi:
             self._copy_grub_config_to_efi_path(
@@ -1491,6 +1496,25 @@ def _fix_grub_loader_entries_boot_cmdline(self):
                 with open(menu_entry_file, 'w') as grub_menu_entry_file:
                     grub_menu_entry_file.write(menu_entry)
 
+    def grub_loader_entries_boot_cmdline_append(self):
+        if self.cmdline:
+            loader_entries_pattern = os.sep.join(
+                [
+                    self.root_mount.mountpoint,
+                    'boot', 'loader', 'entries', '*.conf'
+                ]
+            )
+            for menu_entry_file in glob.iglob(loader_entries_pattern):
+                with open(menu_entry_file) as grub_menu_entry_file:
+                    menu_entry = grub_menu_entry_file.read()
+                    menu_entry = re.sub(
+                        r'options (.*)',
+                        r'options \1 {0}'.format(self.cmdline),
+                        menu_entry
+                    )
+                with open(menu_entry_file, 'w') as grub_menu_entry_file:
+                    grub_menu_entry_file.write(menu_entry)
+
     def _fix_grub_loader_entries_linux_and_initrd_paths(self):
         # For the same reasons encoded in _fix_grub_loader_entries_boot_cmdline
         # this method exists. In this method the wrong paths to the linux