LU-10670 test: make sanity-flr test_43 more reliable

LU-10670 test: make sanity-flr test_43 more reliable

Improve sanity-flr test_43 more reliable by setting the active
state of OSP device instead of OSC device to simulate OST's
unavailability.

Test-Parameters: testlist=sanity-flr
Signed-off-by: Bobi Jam <bobijam.xu@intel.com>
Change-Id: Ibfb4a54479a7dafff251dd3645b03ec172b6884e
Reviewed-on: https://review.whamcloud.com/31315
Tested-by: Jenkins
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Nunez <james.a.nunez@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>