Create these symlinks, since NixOS (and other users) can still be using
the old names:
dosfsck -> fsck.fat
dosfslabel -> fatlabel
fsck.msdos -> fsck.fat
fsck.vfat -> fsck.fat
mkdosfs -> mkfs.fat
mkfs.msdos -> mkfs.fat
mkfs.vfat -> mkfs.fat
While at it, kill the makeFlags which seems unnecessary as it seems
to use a standard Autotools build (maybe this is a new thing).
346482c8d5