Use inline literal markup for options in releasenotes

This commit makes the releasenotes to use 'inline literal markup[0]
because it would be accurate rendering for commandline
options. Otherwise, dashes are changed into an en/em dash entity. And
this commit also fixes some inline literal markups which I
noticed. Ideally, we should fix like that things in one
patch. However, it's a bit hard to find them all..

[0] http://www.sphinx-doc.org/en/master/usage/restructuredtext/basics.html#roles

Change-Id: I8f7691b3ff40ccde051620f44217dab244d76960
diff --git a/releasenotes/notes/16/16.0.0-remove-deprecated-compute-validation-config-options-part-2-5cd17b6e0e6cb8a3.yaml b/releasenotes/notes/16/16.0.0-remove-deprecated-compute-validation-config-options-part-2-5cd17b6e0e6cb8a3.yaml
index b4e4dd1..c8b0ca8 100644
--- a/releasenotes/notes/16/16.0.0-remove-deprecated-compute-validation-config-options-part-2-5cd17b6e0e6cb8a3.yaml
+++ b/releasenotes/notes/16/16.0.0-remove-deprecated-compute-validation-config-options-part-2-5cd17b6e0e6cb8a3.yaml
@@ -8,4 +8,4 @@
     - ``compute.ssh_user`` (available as ``validation.image_ssh_user``)
     - ``scenario.ssh_user`` (available as ``validation.image_ssh_user``)
     - ``compute.network_for_ssh`` (available as ``validation.network_for_ssh``)
-    - ``compute.ping_timeout `` (available as ``validation.ping_timeout``)
+    - ``compute.ping_timeout`` (available as ``validation.ping_timeout``)