LU-14935 tests: Use FAIL_CHECK_QUIET for fake i/o

LU-14935 tests: Use FAIL_CHECK_QUIET for fake i/o

Logging to the console is relatively expensive and doing it
for fake i/o is very expensive in terms of CPU time.

If we use FAIL_CHECK_QUIET, a debug message is logged only once
to the console, and the rest at D_INFO level (probably not at all).

This should hugely reduce the CPU cost of the debugging.

Signed-off-by: Patrick Farrell <pfarrell@whamcloud.com>
Change-Id: I46a5042efd116a4f5c80eaf0d5dae7fe132f6a79
Reviewed-on: https://review.whamcloud.com/44651
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Etienne AUJAMES <eaujames@ddn.com>