KUDU-239: Recovery dir exists, but log dir doesn't
KUDU-239: Recovery dir exists, but log dir doesn't

This revision handles the case where a recovery dir exists, but log
directory doesn't: a rare occurance -- only happens if there's an
interruption right after the log directory is moved to the recovery
dir, but right before a new log directory is created -- but one that
can cause data loss.

Change-Id: Ic777f6751e58d42172ea6ccb6ff96952f3ceb4b4
Reviewed-on: http://gerrit.ent.cloudera.com:8080/2350
Tested-by: jenkins
Reviewed-by: Todd Lipcon <2c763d726a8c2f6afda9be7e0e56a2caa6bb5e6b@cloudera.com>

EvilMcJerkface/kudu,cloudera/kudu,andrwng/kudu,EvilMcJerkface/kudu,cloudera/kudu,cloudera/kudu,andrwng/kudu,EvilMcJerkface/kudu,InspurUSA/kudu,EvilMcJerkface/kudu,helifu/kudu,InspurUSA/kudu,EvilMcJerkface/kudu,EvilMcJerkface/kudu,helifu/kudu,andrwng/kudu,InspurUSA/kudu,helifu/kudu,InspurUSA/kudu,cloudera/kudu,InspurUSA/kudu,EvilMcJerkface/kudu,cloudera/kudu,cloudera/kudu,andrwng/kudu,helifu/kudu,andrwng/kudu,InspurUSA/kudu,cloudera/kudu,andrwng/kudu,helifu/kudu,InspurUSA/kudu,helifu/kudu,andrwng/kudu,InspurUSA/kudu,cloudera/kudu,EvilMcJerkface/kudu,helifu/kudu,helifu/kudu,EvilMcJerkface/kudu,helifu/kudu,andrwng/kudu,cloudera/kudu,andrwng/kudu,InspurUSA/kudu