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

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

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

Test-Parameters: trivial testlist=recovery-small
Signed-off-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Change-Id: I2db37f0579770ab5a51baf5db832d1f316e7cb14
Reviewed-on: https://review.whamcloud.com/46841
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>