rbd: replace usage of found with dedicated list iterator variable

To move the list iterator variable into the list_for_each_entry_*()
macro in the future it should be avoided to use the list iterator
variable after the loop body.

To *never* use the list iterator variable after the loop it was
concluded to use a separate iterator variable instead of a
found boolean.

This removes the need to use a found variable and simply checking if
the variable was set, can determine if the break/goto was hit.

Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

drivers/block/rbd.c

@@ -756,24 +756,23 @@ static struct rbd_client *__rbd_get_client(struct rbd_client *rbdc)
  */
 static struct rbd_client *rbd_client_find(struct ceph_options *ceph_opts)
 {
-	struct rbd_client *client_node;
-	bool found = false;
+	struct rbd_client *rbdc = NULL, *iter;
 
 	if (ceph_opts->flags & CEPH_OPT_NOSHARE)
 		return NULL;
 
 	spin_lock(&rbd_client_list_lock);
-	list_for_each_entry(client_node, &rbd_client_list, node) {
-		if (!ceph_compare_options(ceph_opts, client_node->client)) {
-			__rbd_get_client(client_node);
+	list_for_each_entry(iter, &rbd_client_list, node) {
+		if (!ceph_compare_options(ceph_opts, iter->client)) {
+			__rbd_get_client(iter);
 
-			found = true;
+			rbdc = iter;
 			break;
 		}
 	}
 	spin_unlock(&rbd_client_list_lock);
 
-	return found ? client_node : NULL;
+	return rbdc;
 }
 
 /*