TrivialFix of Import JSON
TrivialFix of Import JSON

As per the comment#12 in [1], the if loop can be removed
and json can be directly imported from bench.py

[1]: https://review.openstack.org/#/c/264486/

TrivialFix
Depends-On:I7c8a1a39f0e86cbd38466c2dcd611a8f513c8adc
Change-Id: I519753b0db0d8eee70c84afa92dfab2b943afbac

openstack/swift-bench,openstack/swift-bench