LU-7482 tests: fix uninitialized value in llapi_hsm_test

LU-7482 tests: fix uninitialized value in llapi_hsm_test

llapi_hsm_user_request_alloc doesn't zero the memory, so all the
fields in the returned structure must be set.

Signed-off-by: frank zago <fzago@cray.com>
Change-Id: Ib2d99138a5bab6253c00da5d48ebb90e9679e235
Reviewed-on: http://review.whamcloud.com/17364
Reviewed-by: Aurelien Degremont <aurelien.degremont@cea.fr>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>