LU-6638 test: wait for grace delay in sanity-hsm test_37()

LU-6638 test: wait for grace delay in sanity-hsm test_37()

In sanity-hsm test_37(), allow the previous archive request to expire
from the actions log by calling wait_for_grace_delay().

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Change-Id: I42fe4eec44734a9afd59f67d4532c1fe23402269
Reviewed-on: http://review.whamcloud.com/21284
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Frank Zago <fzago@cray.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>