Revert "hack/tf-fmt: Add a workaround for origin/release's hardcoding v0.11.7"

This reverts commit 856350d, openshift#218.

openshift/release@bbb02d36 (Bump Terraform from 0.11.7 to 0.11.8,
2018-09-14, openshift/release#1515) has landed, so we can drop the
workaround.

Author: wking

hack/tf-fmt.sh

@@ -6,7 +6,7 @@ if [ "$IS_CONTAINER" != "" ]; then
     set -- -list -check -write=false
   fi
   set -x
-  /terraform fmt "${@}"  # FIXME: drop this slash after we update openshift/release
+  terraform fmt "${@}"
 else
   podman run --rm \
     --env IS_CONTAINER=TRUE \