LU-12795 tests: Introduce FAILF and start using it

LU-12795 tests: Introduce FAILF and start using it

Unify the sprintf(msg, ...); FAIL(msg); pattern into a single
FAILF() macro and avoid the needless use of a temporary buffer.

Remove the duplicate lp_utils.c and lp_utils.h files.

Signed-off-by: Shaun Tancheff <stancheff@cray.com>
Change-Id: Ia0ed463e305ec671909a049d847eb8518291f72f
Reviewed-on: https://review.whamcloud.com/36255
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Arshad Hussain <arshad.super@gmail.com>
Reviewed-by: Petros Koutoupis <pkoutoupis@cray.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>