Fix dd wipe call.
Fix dd wipe call.

This should have gone in w/ commit 7295abb857b58b04e913493dcb773c22c41e1265.

Signed-off-by: mulhern <7b51bcf507bcd7afb72bf8663752c0ddbeb517f6@redhat.com>

vojtechtrefny/blivet,AdamWill/blivet,rhinstaller/blivet,jkonecny12/blivet,vpodzime/blivet,rhinstaller/blivet,vpodzime/blivet,dwlehman/blivet,rvykydal/blivet,dwlehman/blivet,AdamWill/blivet,vojtechtrefny/blivet,rvykydal/blivet,jkonecny12/blivet