Remove support for nova-volume

* nova-volume has been removed in Grizzly
* part of delete-nova-volume

Change-Id: Iba91d69950767823d77aaaa93243b0f476dbb04d
diff --git a/exercises/volumes.sh b/exercises/volumes.sh
index 72c8729..6892739 100755
--- a/exercises/volumes.sh
+++ b/exercises/volumes.sh
@@ -9,7 +9,7 @@
 echo "*********************************************************************"
 
 # This script exits on an error so that errors don't compound and you see
-# only the first error that occured.
+# only the first error that occurred.
 set -o errexit
 
 # Print the commands being run so that we can see the command that triggers
@@ -33,9 +33,9 @@
 # Import exercise configuration
 source $TOP_DIR/exerciserc
 
-# If cinder or n-vol are not enabled we exit with exitcode 55 which mean
+# If cinder is not enabled we exit with exitcode 55 which mean
 # exercise is skipped.
-is_service_enabled cinder n-vol || exit 55
+is_service_enabled cinder || exit 55
 
 # Instance type to create
 DEFAULT_INSTANCE_TYPE=${DEFAULT_INSTANCE_TYPE:-m1.tiny}