LU-8078 iokit: correct obdfilter-survey output data format

A space is needed between min and max status numbers in the
obdfilter-survey script, otherwise plot-obdfilter can't parse
the summary file correctly, so that the related .dat files and
graphs can't be generated correctly.

Test-Parameters: trivial testlist=obdfilter-survey
Signed-off-by: Emoly Liu <emoly.liu@intel.com>
Change-Id: I5bf4790f2db1ee11cb6a7cc95d5527cb0d68e35a
Reviewed-on: http://review.whamcloud.com/19841
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Bobi Jam <bobijam@hotmail.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>