Remove support for nova-volume

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

Change-Id: Iba91d69950767823d77aaaa93243b0f476dbb04d
diff --git a/exercises/boot_from_volume.sh b/exercises/boot_from_volume.sh
index b06c8dd..4562ac0 100755
--- a/exercises/boot_from_volume.sh
+++ b/exercises/boot_from_volume.sh
@@ -35,9 +35,9 @@
 # Import exercise configuration
 source $TOP_DIR/exerciserc
 
-# If cinder or n-vol are not enabled we exit with exitcode 55 so that
+# If cinder is not enabled we exit with exitcode 55 so that
 # the exercise is skipped
-is_service_enabled cinder n-vol || exit 55
+is_service_enabled cinder || exit 55
 
 # Boot this image, use first AMI image if unset
 DEFAULT_IMAGE_NAME=${DEFAULT_IMAGE_NAME:-ami}