don't call blobutil directly from lbmk

it's bloat, and was only there for backwards compatibility
with the old commands, but the new commands are e.g.

./update blobs inject

instead of:

./blobutil inject

this results in a slight code size reduction in lbmk

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

resources/scripts/update/blobs/download

@@ -386,7 +386,7 @@ extract_ec()
 	if [ ! -f ec.bin ]; then
 		printf "could not extract ec.bin for board '%s'" ${board} \
 			1>&2
-		fail "aborting the build. please audit blobutil carefully."
+		fail "aborting the build. please audit lbmk carefully."
 	fi
 
 	"${kbc1126_ec_dump}" ec.bin