sys-apps/hashboot: Fix incorrect source variable

When downloading the hashboot tarball, e.g. `hashboot-0.9.14.tar.gz` it
extracts to a folder without the version name, so `hashboot`.

This breaks when trying to `emerge hashboot` because the ebuild is
looking for the source code in
`/var/tmp/portage/sys-apps/hashboot-0.9.14/work/hashboot-0.9.14` when
it's actually located at
`/var/tmp/portage/sys-apps/hashboot-0.9.14/work/hashboot`.

In the ebuild that the `P` variable resolves to `hashboot-0.9.14`
and by default `S` and `P` are the same. `S` is what Portage uses to
figure out where the source is, which is why it's trying to find it in
`/var/tmp/portage/sys-apps/hashboot-0.9.14/work/hashboot-0.9.14`.

I managed to get it to build by editing the ebuild to set the `S`
variable as so: `S="${WORKDIR}/${PN}"`, which is what this commit
adds to the ebuild.

sys-apps/hashboot/hashboot-0.9.14.ebuild

@@ -15,6 +15,8 @@ IUSE="firmware"
 RDEPEND="firmware? ( sys-apps/flashrom )"
 DEPEND="app-text/asciidoc"
 
+S="${WORKDIR}/${PN}"
+
 pkg_preinst() {
 	if grep -q '^rc_parallel="YES"' /etc/rc.conf; then
 		ewarn "hashboot does not work properly with parallel boot enabled."

sys-apps/hashboot/hashboot-9999.ebuild

@@ -17,6 +17,8 @@ IUSE="firmware"
 RDEPEND="firmware? ( sys-apps/flashrom )"
 DEPEND="app-text/asciidoc"
 
+S="${WORKDIR}/${PN}"
+
 pkg_preinst() {
 	if grep -q '^rc_parallel="YES"' /etc/rc.conf; then
 		ewarn "hashboot does not work properly with parallel boot enabled."