LU-6125 test: sanity test_27i defect: missing test_mkdir()

LU-6125 test: sanity test_27i defect: missing test_mkdir()

Fix sanity test_27i() to call test_mkdir()

Signed-off-by: Elena Gryaznova <elena.gryaznova@seagate.com>
Xyratex-bug-id: MRP-1194
Reviewed-by: Alexander Zarochentsev <alexander_zarochentsev@xyratex.com>
Change-Id: I093cb44590b98857189d69d1b8f6e9e9c423d3bc
Reviewed-on: http://review.whamcloud.com/13407
Tested-by: Jenkins
Reviewed-by: James Nunez <james.a.nunez@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>