LU-1779 tests: fix run_one_logged() to log SKIP status

LU-1779 tests: fix run_one_logged() to log SKIP status

In the current test framework, only those tests which are in the
$ALWAYS_EXCEPT list are logged with SKIP status, other skipped
tests are all logged with PASS status.

This patch fixes the above issue by setting the SKIP status in
pass() and logging the status in run_one_logged().

Signed-off-by: Yu Jian <yujian@whamcloud.com>
Change-Id: I7d4e66982a04d8759e887d88d0e406da719c03bf
Reviewed-on: http://review.whamcloud.com/3899
Tested-by: Hudson
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>