[klibc] Add swap support to fstype, second version

[H. Peter Anvin]

Kay Sievers wrote:
> 
> Why are you guys need to reinvent everything again? We have full-featured
> klibc ready code for all common fs's in the udev tree:
>   http://www.kernel.org/git/?p=linux/hotplug/udev.git;a=blob;hb=HEAD;f=extras/volume_id/README
> 

Looked at this from a technical perspective; one thing kinit needs is to 
be able to query the size of the filesystem from the data, as opposed 
from the block size.  Something that also would be nice for using this 
code in kinit would be to break the filesystem and RAID probes out 
separately.

However, I think for right now there are bigger fish to fry.  In the 
long term, though, it would be good to work from one codebase instead of 
two, assuming the needs of both can be met.

	-hpa