IB/core: Shuffle locks in ib_port_data to save memory

pahole shows two 4-byte holes in struct ib_port_data after pkey_list_lock
and netdev_lock respectively.

Shuffling the netdev_lock to be after pkey_list_lock, this shaves off
eight bytes from the struct.

Link: https://lore.kernel.org/r/20210616154509.1047-3-anand.a.khoje@oracle.comSuggested-by: Haakon Bugge <haakon.bugge@oracle.com>
Signed-off-by: Anand Khoje <anand.a.khoje@oracle.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

include/rdma/ib_verbs.h

@@ -2176,11 +2176,13 @@ struct ib_port_data {
 	struct ib_port_immutable immutable;
 
 	spinlock_t pkey_list_lock;
+
+	spinlock_t netdev_lock;
+
 	struct list_head pkey_list;
 
 	struct ib_port_cache cache;
 
-	spinlock_t netdev_lock;
 	struct net_device __rcu *netdev;
 	struct hlist_node ndev_hash_link;
 	struct rdma_port_counter port_counter;