contrib: explicitly pass "-n" to "nm-code-format.sh" in "code-style-git-post-commit-hook"

"nm-code-format.sh" is going to change the default behavior from "-n" to
"-i", that is, from check-only to reformat. Explicitly pass "-n" where
we want it.

contrib/scripts/code-style-git-post-commit-hook

@@ -17,5 +17,5 @@ CHANGED_FILES=$(git log --pretty='' --name-only -n1 | grep -E '\.c$|\.h$' | tr '
 echo $CHANGED_FILES
 
 if [ -x "$FORMATTER" ] && [ ! -z "$CHANGED_FILES" ]; then
-    "$FORMATTER" "${CHANGED_FILES}"
+    "$FORMATTER" -n "${CHANGED_FILES}"
 fi