svc: Move kfree of deferral record to common code

The rqstp structure has a pointer to a svc_deferred_req record
that is allocated when requests are deferred. This record is common
to all transports and can be freed in common code.

Move the kfree of the rq_deferred to the common svc_xprt_release
function.

This also fixes a memory leak in the RDMA transport which does not
kfree the dr structure in it's version of the xpo_release_rqst callback.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

net/sunrpc/svc_xprt.c

@@ -448,6 +448,9 @@ static void svc_xprt_release(struct svc_rqst *rqstp)
 
 	rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp);
 
+	kfree(rqstp->rq_deferred);
+	rqstp->rq_deferred = NULL;
+
 	svc_free_res_pages(rqstp);
 	rqstp->rq_res.page_len = 0;
 	rqstp->rq_res.page_base = 0;

net/sunrpc/svcsock.c

@@ -103,7 +103,6 @@ static void svc_reclassify_socket(struct socket *sock)
 static void svc_release_skb(struct svc_rqst *rqstp)
 {
 	struct sk_buff *skb = rqstp->rq_xprt_ctxt;
-	struct svc_deferred_req *dr = rqstp->rq_deferred;
 
 	if (skb) {
 		struct svc_sock *svsk =
@@ -113,10 +112,6 @@ static void svc_release_skb(struct svc_rqst *rqstp)
 		dprintk("svc: service %p, releasing skb %p\n", rqstp, skb);
 		skb_free_datagram(svsk->sk_sk, skb);
 	}
-	if (dr) {
-		rqstp->rq_deferred = NULL;
-		kfree(dr);
-	}
 }
 
 union svc_pktinfo_u {