NFSv4.1: don't export static symbol

The semantic patch that fixes this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r@
type T;
identifier f;
@@

static T f (...) { ... }

@@
identifier r.f;
declarer name EXPORT_SYMBOL_GPL;
@@

-EXPORT_SYMBOL_GPL(f);
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

fs/nfs/pnfs.c

@@ -1902,7 +1902,6 @@ static void pnfs_writehdr_free(struct nfs_pgio_header *hdr)
 	pnfs_put_lseg(hdr->lseg);
 	nfs_pgio_header_free(hdr);
 }
-EXPORT_SYMBOL_GPL(pnfs_writehdr_free);
 
 int
 pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
@@ -2032,7 +2031,6 @@ static void pnfs_readhdr_free(struct nfs_pgio_header *hdr)
 	pnfs_put_lseg(hdr->lseg);
 	nfs_pgio_header_free(hdr);
 }
-EXPORT_SYMBOL_GPL(pnfs_readhdr_free);
 
 int
 pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)