node_exporter: Use real tempfile

roles/node_exporter/files/node-exporter-run-textfile-collector.sh

@@ -15,9 +15,10 @@ fi
 for script in /usr/local/libexec/node-exporter/*; do
     [ -x "$script" ] || continue
     target="${OUTDIR}/$(basename "$script")"
-    if "$script" > "${target}.tmp" ; then
-        mv "${target}.tmp" "${target}.prom"
+    tmpfile="$(mktemp -p "$OUTDIR")"
+    if "$script" > "$tmpfile" ; then
+        mv "$tmpfile" "$target"
     else
-        rm -f "${target}.tmp"
+        rm -f "$tmpfile"
     fi
 done