dm: rename request variables to bios

Use 'bio' in the name of variables and functions that deal with
bios rather than 'request' to avoid confusion with the normal
block layer use of 'request'.

No functional changes.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 2ae151e..13c1548 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1637,7 +1637,7 @@
 
 		if (opt_params == 1 && opt_string &&
 		    !strcasecmp(opt_string, "allow_discards"))
-			ti->num_discard_requests = 1;
+			ti->num_discard_bios = 1;
 		else if (opt_params) {
 			ret = -EINVAL;
 			ti->error = "Invalid feature arguments";
@@ -1665,7 +1665,7 @@
 		goto bad;
 	}
 
-	ti->num_flush_requests = 1;
+	ti->num_flush_bios = 1;
 	ti->discard_zeroes_data_unsupported = true;
 
 	return 0;
@@ -1726,7 +1726,7 @@
 		DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
 				cc->dev->name, (unsigned long long)cc->start);
 
-		if (ti->num_discard_requests)
+		if (ti->num_discard_bios)
 			DMEMIT(" 1 allow_discards");
 
 		break;