LU-4458 test: take fail_val into account for pause_bulk()

LU-4458 test: take fail_val into account for pause_bulk()

pause_bulk(), set_nodes_failloc() and reset_fail_loc() should
care about fail_val as well for compatibility with master

Signed-off-by: Mikhail Pershin <mike.pershin@intel.com>
Change-Id: I283a23c67a633a5db479e421c96c164e1e07d05c
Reviewed-on: http://review.whamcloud.com/13205
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Li Wei <wei.g.li@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>