MB-36926: Reduce indentation of EPBucket::flushVBucket
MB-36926: Reduce indentation of EPBucket::flushVBucket

Invert the if(vb) condition to reduce the overall indentation of
the function. In a later patch I'll add an additional scope and
increase the indentation of sections of the function.

Change-Id: I772a36da49af9c2c36d909cf89cd93c32d30dd8d
Reviewed-on: http://review.couchbase.org/118972
Well-Formed: Build Bot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Trond Norbye <60edd2ef23891a753f231b0c6f161dc634079a93@couchbase.com>
Tested-by: Build Bot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>

daverigby/kv_engine,daverigby/kv_engine,daverigby/kv_engine,daverigby/kv_engine