release: correct VMSIZE example/documentation

[gjb]

Summary

release/release.sh originally used truncate to create empty image
files and then created filesystems in those. Now the script uses
makefs and the size specification is different. Update the sample
configuration and man page to reflect this.

[ehem_freebsd_m5p.com]

This is fallout from D28912/1ca8842f3ad9725863c9affc044d1974a51818a9. Problem is case differs between truncate and makefs.

Ideally there needs to be a substantial warning about this since spending hours to do a build only to have it fail just before the end is very annoying.

I should also note while the particular build failed, the build did not terminate! I suspect D28912 needs a bit of extra error checking.

[ehem_freebsd_m5p.com]

Actually, there also seems to be a good argument for makefs -s being able to handle any size acceptable to truncate -s.

[ehem_freebsd_m5p.com]

I've got a patch to add uppercase letters to strsufftoll(), this would make makefs accept uppercase letters and keep older configurations functioning.

[nwhitehorn]

We could also have makefs use expand_number(3) instead. Apologies for breakage!

[gjb]

Thank you for the submission. In addition to your proposed patch, I have also updated the VMSIZE set in release/tools/*.conf.