[PATCH] NFSv4: Fix an Oops in the callback code.

The changeset "trond.myklebust@fys.uio.no|ChangeSet|20050322152404|16979"
 (RPC: Ensure XDR iovec length is initialized correctly in call_header)
 causes the NFSv4 callback code to BUG() due to an incorrectly initialized
 scratch buffer.

 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/callback_xdr.c

@@ -411,7 +411,6 @@ static int nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *resp
 	xdr_init_decode(&xdr_in, &rqstp->rq_arg, rqstp->rq_arg.head[0].iov_base);
 
 	p = (uint32_t*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
-	rqstp->rq_res.head[0].iov_len = PAGE_SIZE;
 	xdr_init_encode(&xdr_out, &rqstp->rq_res, p);
 
 	decode_compound_hdr_arg(&xdr_in, &hdr_arg);