WorkStruct: Separate delayable and non-delayable events.

Separate delayable work items from non-delayable work items be splitting them
into a separate structure (delayed_work), which incorporates a work_struct and
the timer_list removed from work_struct.

The work_struct struct is huge, and this limits it's usefulness.  On a 64-bit
architecture it's nearly 100 bytes in size.  This reduces that by half for the
non-delayable type of event.

Signed-Off-By: David Howells <dhowells@redhat.com>
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 5fea638..6f0487d 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -143,7 +143,7 @@
 	INIT_LIST_HEAD(&clp->cl_state_owners);
 	INIT_LIST_HEAD(&clp->cl_unused);
 	spin_lock_init(&clp->cl_lock);
-	INIT_WORK(&clp->cl_renewd, nfs4_renew_state, clp);
+	INIT_DELAYED_WORK(&clp->cl_renewd, nfs4_renew_state, clp);
 	rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client");
 	clp->cl_boot_time = CURRENT_TIME;
 	clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;