fixed ci

ci/run-rustfmt.sh

@@ -4,10 +4,7 @@ ERROR=0
 
 while IFS= read -r -d '' f; do
   echo "${f}"
-
-  if  [ "$(rustfmt --write-mode=diff "$f")" != $'' ]  ; then
-      ERROR=1
-  fi
+  rustfmt --write-mode=diff "$f" || ERROR=1
 done < <(find . -type f -name '*.rs' -print0)
 
 exit ${ERROR}