/usr/local/grub2/sbin/grub-install: info: grub-mkimage --directory '/usr/local/grub2/lib/grub/i386-pc' --prefix '(mduuid/e6d1dcf06cea72140bafae74a8677f36)/grub' --output '/boot/grub/i386-pc/core.img' --format 'i386-pc' --compression 'auto' 'ext2' 'msdos' 'msdos' 'diskfilter' 'mdraid1x' 'biosdisk'
.
/usr/local/grub2/sbin/grub-install: error: cannot open `/usr/local/grub2/lib/grub/i386-pc/msdos.mod': No such file or directory.
Introduce common helper for both diskfilter and non-diskfilter case that
converts partition map names into module names.