bug-fix: fix key error in soak throughputs CI

In the redundant information deleting patch, results of each
thread running is removed from message Queue resulting in
counting the overall success threads in error status

Change-Id: I3d12ddcc3ef996fca509741544a0f088428e948e
Signed-off-by: Yang Yu <Gabriel.yuyang@huawei.com>
(cherry picked from commit 68b91c0679550efe005278f8689b57bf14092ee1)