trivial: Fix reno typos

This patchset fixes reno typos in a file that were highlighted
in review I57a0be85b0da8dd13dd36b419b9be8feec151d88. This
included a redundant preposition and missing period. This corrects
those issues.

Change-Id: I190acb1a2297804faca53e0a2dd6a3f2cb0db908
diff --git a/releasenotes/notes/add-show-quota-details-api-to-network-quotas-client-3fffd302cc5d335f.yaml b/releasenotes/notes/add-show-quota-details-api-to-network-quotas-client-3fffd302cc5d335f.yaml
index bbb11dd..6c44ba0 100644
--- a/releasenotes/notes/add-show-quota-details-api-to-network-quotas-client-3fffd302cc5d335f.yaml
+++ b/releasenotes/notes/add-show-quota-details-api-to-network-quotas-client-3fffd302cc5d335f.yaml
@@ -3,5 +3,5 @@
   - |
     Add extension API show quota details to network quotas_client library.
     This feature enables the possibility to show a quota set for a specified
-    project that includes the quota's used, limit and reserved counts for per
-    resource
+    project that includes the quota's used, limit and reserved counts per
+    resource.