futility: stop using the symlink names in utility scripts

We still create the symlinks (FOO -> futility), but this
change invokes those built-in functions with "futility FOO ..."
instead of using the FOO symlink.

Note that the scripts/ directory is unchanged. That's a
separate CL, since we don't have tests for that.

BUG=chromium:231547
BRANCH=ToT
TEST=make runtests

In addition to running "make runtests", I temporarily
modified the Makefile to avoid creating the symlinks at all.
The tests still passed.

Change-Id: I96863259b9df02a3611f759a7509bf4090ae03e8
Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/216717
Reviewed-by: Randall Spangler <rspangler@chromium.org>
diff --git a/tests/run_preamble_tests.sh b/tests/run_preamble_tests.sh
index 80deebb..df2f54f 100755
--- a/tests/run_preamble_tests.sh
+++ b/tests/run_preamble_tests.sh
@@ -41,7 +41,8 @@
       fi
       : $(( tests++ ))
       echo -n "${what} fw_${d}_${r}.vblock with root_${rr}.vbpubk ... "
-      "${BIN_DIR}/vbutil_firmware" --verify "${V2DIR}/fw_${d}_${r}.vblock" \
+      "${FUTILITY}" vbutil_firmware \
+        --verify "${V2DIR}/fw_${d}_${r}.vblock" \
         --signpubkey "${DATADIR}/root_${rr}.vbpubk" \
         --fv "${DATADIR}/FWDATA" >/dev/null 2>&1
       if [ "$?" "$cmp" 0 ]; then
@@ -68,7 +69,8 @@
       fi
       : $(( tests++ ))
       echo -n "${what} kern_${d}_${r}.vblock with root_${rr}.vbpubk ... "
-      "${BIN_DIR}/vbutil_kernel" --verify "${V2DIR}/kern_${d}_${r}.vblock" \
+      "${FUTILITY}" vbutil_kernel \
+        --verify "${V2DIR}/kern_${d}_${r}.vblock" \
         --signpubkey "${DATADIR}/root_${rr}.vbpubk" >/dev/null 2>&1
       if [ "$?" "$cmp" 0 ]; then
         echo -e "${COL_RED}FAILED${COL_STOP}"
@@ -86,7 +88,7 @@
   for r in $algs; do
       : $(( tests++ ))
       echo -n "verify kern_${d}_${r}.vblock with hash only ... "
-      "${BIN_DIR}/vbutil_kernel" \
+      "${FUTILITY}" vbutil_kernel \
           --verify "${V2DIR}/kern_${d}_${r}.vblock" >/dev/null 2>&1
       if [ "$?" -ne 0 ]; then
         echo -e "${COL_RED}FAILED${COL_STOP}"