nvme: multipath: fix return value of nvme_available_path

The function returns bool so we should return false, not NULL. No
functional changes are expected.

Signed-off-by: Uday Shankar <ushankar@purestorage.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Author: ps-ushankar

drivers/nvme/host/multipath.c

@@ -427,7 +427,7 @@ static bool nvme_available_path(struct nvme_ns_head *head)
 	struct nvme_ns *ns;
 
 	if (!test_bit(NVME_NSHEAD_DISK_LIVE, &head->flags))
-		return NULL;
+		return false;
 
 	list_for_each_entry_srcu(ns, &head->list, siblings,
 				 srcu_read_lock_held(&head->srcu)) {