LU-9158 test: Use project ID for project quota for quota_scan

LU-9158 test: Use project ID for project quota for quota_scan

Use project ID instead of quota user for project quota in
function quota_scan. This is not a fix for the rebalancing error,
only correct the test script issue.

Change-Id: I9165ada17de0f32ac38f720a5e9e9be46363b41f
Signed-off-by: Wei Liu <wei3.liu@intel.com>
Reviewed-on: https://review.whamcloud.com/28957
Reviewed-by: Wang Shilong <wshilong@ddn.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Nunez <james.a.nunez@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>