BLS files should only be copied by grub-switch-to-blscfg if BLS isn't set
Related: rhbz#1638117
Fix get_entry_number() wrongly dereferencing the tail pointer
Resolves: rhbz#1654936
Make grub2-mkconfig to honour GRUB_CMDLINE_LINUX in /etc/default/grub
Resolves: rhbz#1637875
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
