Don't fail 920addTestcases if it doesn't find the test modules.

This allows us to build a sonic "test" image successfully (it's in
quotes because it's not a fully functional test image yet).

BUG=chromium:220368
TEST=build_image test for sonic and daisy, inspected build logs

Change-Id: Ic51ace9206e90428df3bc4cad929b94e81efa46a
Reviewed-on: https://gerrit.chromium.org/gerrit/57387
Tested-by: Darin Petkov <petkov@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Darin Petkov <petkov@chromium.org>
diff --git a/mod_for_test_scripts/920addTestcases b/mod_for_test_scripts/920addTestcases
index 9144fc1..1154547 100755
--- a/mod_for_test_scripts/920addTestcases
+++ b/mod_for_test_scripts/920addTestcases
@@ -9,7 +9,12 @@
 
 echo "Adding the kernel test modules for autotest runs."
 MODULES_PATH="/lib/modules"
-KERNEL_RELEASE=$(ls -tr "${ROOT_FS_DIR}${MODULES_PATH}" | tail -n1)
+ROOTFS_MODULES_PATH="${ROOT_FS_DIR}${MODULES_PATH}"
+if [ ! -d "${ROOTFS_MODULES_PATH}" ] ; then
+  echo "${ROOTFS_MODULES_PATH}" does not exist - skipping.
+  exit 0
+fi
+KERNEL_RELEASE=$(ls -tr "${ROOTFS_MODULES_PATH}" | tail -n1)
 TESTCASES_PATH="${MODULES_PATH}/${KERNEL_RELEASE}"
 SRC_DIR="${BOARD_ROOT}${TESTCASES_PATH}"
 DST_DIR="${ROOT_FS_DIR}${TESTCASES_PATH}"