svcrpc: remove unused rq_resused

I forgot to remove this in
afc59400 "nfsd4: cleanup: replace
rq_resused count by rq_next_page pointer".
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

include/linux/sunrpc/svc.h

@@ -243,7 +243,6 @@ struct svc_rqst {
 	struct xdr_buf		rq_res;
 	struct page *		rq_pages[RPCSVC_MAXPAGES];
 	struct page *		*rq_respages;	/* points into rq_pages */
-	int			rq_resused;	/* number of pages used for result */
 	struct page *		*rq_next_page; /* next reply page to use */
 
 	struct kvec		rq_vec[RPCSVC_MAXPAGES]; /* generally useful.. */