Make tox-linters run the tox/linters play

This looks like it was a sad copy-paste.

Change-Id: If253a1d67d5ed08d6bcd8506bcc29f4e51f45e97
diff --git a/.zuul.yaml b/.zuul.yaml
index 98b880d..50223fa 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -31,7 +31,7 @@
 - job:
     name: tox-linters
     parent: tox
-    run: tox/docs
+    run: tox/linters
 
 - job:
     name: tox-py27