Only destroy the storage area that had trouble.

Consider the case where CE failed to prepare; we'd destroy both DE
and CE, but then only recreate CE.  This change makes sure we only
destroy something we're willing to recreate.

Bug: 62338545
Test: builds, boots
Change-Id: I566791b59b35a30db70b0de3acfe624b239bf5d2
1 file changed