Fix broken disklabel (bnc#879147)

Signed-off-by: Dinar Valeev <dvaleev@suse.com>
Merge pull request #48 from k0da/master

Fix broken disklabel (bnc#879147)
GRUB_BIOS partitions must not be formated
adapted to suggestions
Merge pull request #49 from yast/review_140603_grub_bios_partitions

GRUB_BIOS partitions must not be formated