vol: Move destroyMe check outside of inUse check

vol: Move destroyMe check outside of inUse check

The destroyMe conditional does not depend on the result of
VShouldCheckInUse(), so move it outside of that block.

Change-Id: Ieb4c97ae9f76b4369680629f18eecd1dfc06682f
Reviewed-on: http://gerrit.openafs.org/2276
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Reviewed-by: Tom Keiser <tkeiser@sinenomine.net>
Tested-by: Derrick Brashear <shadow@dementia.org>