Update links to avoid redirects. (#5627)

* Update links to avoid redirects.

* Fix double forward slash.

docs/concepts/workloads/controllers/petset.md

@@ -10,7 +10,7 @@ approvers:
 title: PetSets
 ---
 
-__Warning:__ Starting in Kubernetes version 1.5, PetSet has been renamed to [StatefulSet](/docs/concepts/abstractions/controllers/statefulsets). To use (or continue to use) PetSet in Kubernetes 1.5, you _must_ [migrate](/docs/tasks/manage-stateful-set/upgrade-pet-set-to-stateful-set/) your existing PetSets to StatefulSets. For information on working with StatefulSet, see the tutorial on [how to run replicated stateful applications](/docs/tutorials/stateful-application/run-replicated-stateful-application).
+__Warning:__ Starting in Kubernetes version 1.5, PetSet has been renamed to [StatefulSet](/docs/concepts/abstractions/controllers/statefulsets). To use (or continue to use) PetSet in Kubernetes 1.5, you _must_ [migrate](/docs/tasks/manage-stateful-set/upgrade-pet-set-to-stateful-set/) your existing PetSets to StatefulSets. For information on working with StatefulSet, see the tutorial on [how to run replicated stateful applications](/docs/tasks/run-application/run-replicated-stateful-application/).
 
 __This document has been deprecated__, but can still apply if you're using
   Kubernetes version 1.4 or earlier.
@@ -227,7 +227,7 @@ web-1
 
 A pet can piece together its own identity:
 
-1. Use the [downward api](/docs/tasks/configure-pod-container/downward-api-volume-expose-pod-information/) to find its pod name
+1. Use the [downward api](/docs/tasks/inject-data-application/downward-api-volume-expose-pod-information/) to find its pod name
 2. Run `hostname` to find its DNS name
 3. Run `mount` or `df` to find its volumes (usually this is unnecessary)