LU-11885 test: reset quota upon test failed

LU-11885 test: reset quota upon test failed

Currently if test fail, EXIT will be trapped and
cleanup_quota_test() will be called to cleanup dirs.

However, we didn't reset quota in this case, this might
make following test fail because of this.

Also cleanup duplicated lines sine we have done reseting
inside cleanup_quota_test().

Test-Parameters: trivial testlist=sanity-quota
Signed-off-by: Wang Shilong <wshilong@ddn.com>
Change-Id: Ic70f59cdc1181473721e4f87b806b8203857fca8
Reviewed-on: https://review.whamcloud.com/34108
Tested-by: Jenkins
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: James Nunez <jnunez@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>