md: dm-zoned-target: Initialize return variable r to avoid uninitialized use

Fix Smatch-detected error:
drivers/md/dm-zoned-target.c:1073 dmz_iterate_devices()
error: uninitialized symbol 'r'.

Smatch detects a possible use of the uninitialized variable 'r' in
dmz_iterate_devices() because if dmz->nr_ddevs is zero, the loop is
skipped and 'r' is returned without being set, leading to undefined
behavior.

Initialize 'r' to 0 before the loop. This ensures that if there are no
devices to iterate over, the function still returns a defined value.

Signed-off-by: Purva Yeshi <[email protected]>
Signed-off-by: Mikulas Patocka <[email protected]>

Author: Purva Yeshi

drivers/md/dm-zoned-target.c

@@ -1062,7 +1062,7 @@ static int dmz_iterate_devices(struct dm_target *ti,
 	struct dmz_target *dmz = ti->private;
 	unsigned int zone_nr_sectors = dmz_zone_nr_sectors(dmz->metadata);
 	sector_t capacity;
-	int i, r;
+	int i, r = 0;
 
 	for (i = 0; i < dmz->nr_ddevs; i++) {
 		capacity = dmz->dev[i].capacity & ~(zone_nr_sectors - 1);