Allow upgrade from -BETA and -RC releases

[aryeeteygerald_rogers.com]

Summary

Update to Revision 343122 to include -BETA and -RC releases
as upgrade-able via freebsd-update

Test Plan

None

[emaste]

usr.sbin/freebsd-update/freebsd-update.sh

671

The case body is executed upon a match, so is this not backwards? Also typical FreeBSD style puts the cases on a separate line, so something like:

case ${RELNUM} in
*-RELEASE | *-ALPHA* | *-BETA* | *-RC*)
        ;;
*)
        # error and exit
       ;;
esac

(also adding *-ALPHA* as noted on the svn mailing list)

[emaste]

usr.sbin/freebsd-update/freebsd-update.sh

674

Since we're going to add -ALPHA in here too I might drop the explicit -RELEASE form and make the text read more naturally with something along the lines of "is not a release (or alpha, beta or release candidate)." or "is not a release (including alpha, beta and release candidates)."

[aryeeteygerald_rogers.com]

• Include support for upgrading from alpha releases

Also fix reversed check for illegal releases

[aryeeteygerald_rogers.com]

• Fix spacing issues

[delphij]

LGTM in principal (except the style issue raised by @emaste which is minor and I think he would take care of it when committing).

The two "NO ACTION REQUESTED FOR THIS CHANGESET" comments are issues that beyond the scope of this changeset, but something that we should do.

usr.sbin/freebsd-update/freebsd-update.sh

665

[NO ACTION REQUESTED FOR THIS CHANGESET] We could potentially remove this compatibility shim now.

695

[NO ACTION REQUESTED FOR THIS CHANGESET] We should consider adding a --force option to bypass this kind of checks in a separate changeset.

[emaste]

See also comment on GitHub: https://github.com/freebsd/freebsd/commit/bffa924f13c42550db2ffc74e8b45143c1bd3af4#commitcomment-31992245

[aryeeteygerald_rogers.com]

Need to add export UNAME_r to config_SourceRelease. Will create new review with fix.

[emaste]

In review D18896