RDMA/core: Fix several reference count leaks.

kobject_init_and_add() takes reference even when it fails.  If this
function returns an error, kobject_put() must be called to properly clean
up the memory associated with the object. Previous
commit b8eb718 ("net-sysfs: Fix reference count leak in
rx|netdev_queue_add_kobject") fixed a similar problem.

Link: https://lore.kernel.org/r/20200528030231.9082-1-wu000273@umn.edu
Signed-off-by: Qiushi Wu <wu000273@umn.edu>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/core/sysfs.c

@@ -1058,8 +1058,7 @@ static int add_port(struct ib_core_device *coredev, int port_num)
 				   coredev->ports_kobj,
 				   "%d", port_num);
 	if (ret) {
-		kfree(p);
-		return ret;
+		goto err_put;
 	}
 
 	p->gid_attr_group = kzalloc(sizeof(*p->gid_attr_group), GFP_KERNEL);
@@ -1072,8 +1071,7 @@ static int add_port(struct ib_core_device *coredev, int port_num)
 	ret = kobject_init_and_add(&p->gid_attr_group->kobj, &gid_attr_type,
 				   &p->kobj, "gid_attrs");
 	if (ret) {
-		kfree(p->gid_attr_group);
-		goto err_put;
+		goto err_put_gid_attrs;
 	}
 
 	if (device->ops.process_mad && is_full_dev) {
@@ -1404,8 +1402,10 @@ int ib_port_register_module_stat(struct ib_device *device, u8 port_num,
 
 		ret = kobject_init_and_add(kobj, ktype, &port->kobj, "%s",
 					   name);
-		if (ret)
+		if (ret) {
+			kobject_put(kobj);
 			return ret;
+		}
 	}
 
 	return 0;