LU-15626 tests: Fix "error" reported by shellcheck for recovery-random-scale

LU-15626 tests: Fix "error" reported by shellcheck for recovery-random-scale

This patch fixes "error" issues reported by shellcheck
for file lustre/tests/recovery-random-scale.sh. This
patch also moves spaces to tabs.

Test-Parameters: trivial clientcount=6 mdtcount=2 mdscount=2 osscount=2 austeroptions=-R failover=true iscsi=1 env=FAILOVER_PERIOD=180,SLOW=no testlist=recovery-random-scale
Signed-off-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Change-Id: I9e7c6fcd726d5fc2141a7ced73ea78ee6a43ec22
Reviewed-on: https://review.whamcloud.com/46866
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Jian Yu <yujian@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>