inject.sh: split to vendor.sh the download parts

to the extent feasible, keep lbmk-specific parts on
inject.sh to a minimum. this will later be used to
re-sync cbmk's inject.sh with lbmk's, because cbmk's
one doesn't handle vendor files.

the way this is designed now, with this patch, will
make cherry-picking lbmk to cbmk easier in the future,
when keeping this part of cbmk in sync with lbmk.

Signed-off-by: Leah Rowe <leah@libreboot.org>

include/init.sh

@@ -16,7 +16,7 @@ xbmkpath="$PATH"
 
 eval "`setvars "" _nogit board reinstall versiondate aur_notice configdir \
     datadir version xbmkpwd relname xbmkpwd xbmktmp python pyver xbmklocal \
-    xbmklock`"
+    xbmklock cvxbmk cvchk`"
 
 xbmk_init()
 {