dm delay: support discard

Enable discard support for the delay target.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

authored by Mike Snitzer and committed by Alasdair G Kergon 3fd5d480 f8facb61

+1
+1
drivers/md/dm-delay.c
··· 198 198 atomic_set(&dc->may_delay, 1); 199 199 200 200 ti->num_flush_requests = 1; 201 + ti->num_discard_requests = 1; 201 202 ti->private = dc; 202 203 return 0; 203 204