util-linux: Do not build raw any more.

The man page of the raw tool does not build because the disk-utils/raw.8
file is missing. It looks like it should be in the tar.xz file we
download, but it is missing.

We do not package the raw tool, so this is not a problem.

This fixes the following build error:
No rule to make target 'disk-utils/raw.8', needed by 'all-am'.  Stop.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>