Remove umount check.

  - address Frysinger comments in pervious commit.
  - umount check will be done at mount_gpt_image.sh.

BUG=b:62703887
TEST=Manually

Change-Id: I548a54533ca55a7c47b31cb4f3df32d8f517c938
Reviewed-on: https://chromium-review.googlesource.com/544902
Commit-Ready: danny chan <dchan@chromium.org>
Tested-by: danny chan <dchan@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
diff --git a/fm_and_key_version_test_prep.sh b/fm_and_key_version_test_prep.sh
index 4197139..d143d68 100755
--- a/fm_and_key_version_test_prep.sh
+++ b/fm_and_key_version_test_prep.sh
@@ -26,10 +26,9 @@
 . "${SCRIPT_ROOT}/common.sh" || exit 1
 
 cleanup() {
-  if [ $(df "$STATEFUL_FS_DIR" | grep -c "$STATEFUL_FS_DIR") -eq 1 ]; then
-    "${SCRIPTS_DIR}/mount_gpt_image.sh" -u \
-      -i "$IMAGE_NAME" -f "$WORKING_DIR" -r "$ROOT_FS_DIR" -s "$STATEFUL_FS_DIR"
-  fi
+  "${SCRIPTS_DIR}/mount_gpt_image.sh" -u \
+      -i "${IMAGE_NAME}" -f "${WORKING_DIR}" \
+      -r "${ROOT_FS_DIR}" -s "${STATEFUL_FS_DIR}"
 }
 
 on_exit() {