LU-4028 quota: fix output of 'lfs quota'

LU-4028 quota: fix output of 'lfs quota'

Fix the output of 'lfs quota' when '-h' option is specified:
- total allocated block limit should be converted after calculation;
- show 1~3 digit after the decimal point;

Signed-off-by: Niu Yawei <yawei.niu@intel.com>
Change-Id: I90a8087dc15153c1b0b895c8081fe2882d6d01e6
Reviewed-on: http://review.whamcloud.com/8407
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Johann Lombardi <johann.lombardi@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>