Fix non-export of journal dev boot options.

cmdline_journal does not contain linefeeds anymore, so read
silently skipped it altogether.

Signed-off-by: Thorsten Behrens <tbehrens@suse.com>
Also export root= boot param for hostonly-cmdline case.

If there's a root fallback, at least attempt to have it falling
back to the last root filesystem this system ran off of.

Signed-off-by: Thorsten Behrens <tbehrens@suse.com>
Don't create lots of empty cmdline files for hostonly-cmdline case

This aligns other places piping cmdline() output to cmdline.d files
with the earlier fix for 95rootfs-block.

Signed-off-by: Thorsten Behrens <tbehrens@suse.com>
More empty cmdline fixes

This fixes up some more modules which might print out empty
commandline files.

Signed-off-by: Hannes Reinecke <hare@suse.de>