LU-6142 tests: Remove file iam_ut.c

LU-6142 tests: Remove file iam_ut.c

This patch removes file lustre/tests/iam_ut.c
This file currently is not used at all by any
tests or binary.

Signed-off-by: Arshad Hussain <arshad.super@gmail.com>
Change-Id: Ia27a94a4cc7ed1a5ff788b07ce1f2487f9427c83
Reviewed-on: https://review.whamcloud.com/35818
Reviewed-by: Shaun Tancheff <stancheff@cray.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Ben Evans <bevans@cray.com>
Reviewed-by: Petros Koutoupis <pkoutoupis@cray.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>