There was an error in the logic that stored the parsed BLS snippets in the
sorted linked list that is used to populate the GRUB boot menu entries.
Also add a fix found by coverity scan about a possible undefined behaviour
due grub_efi_status_t having the wrong type.
Resolves: rhbz#1691232
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
