Fix default value for storwize_svc_vol_rsize

The default for storwize_svc_vol_rsize is '2%', should be just 2.

Change-Id: Ief51ad89bceaee043279e03b57c09c2b3f59d0af
Closes-Bug: #1320647
Merge "Fix default value for storwize_svc_vol_rsize"