NFS: Fix a use-before-initialised warning in fs/nfs/write.c and fs/nfs/pnfs.c

If the allocation of nfs_write_header fails, the list of nfs_pages that
needs to be cleaned up is still on desc->pg_list...

Reported-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Fred Isaman <iisaman@netapp.com>
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index fec214b..3636191 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1164,7 +1164,7 @@
 
 	whdr = nfs_writehdr_alloc();
 	if (!whdr) {
-		desc->pg_completion_ops->error_cleanup(&hdr->pages);
+		desc->pg_completion_ops->error_cleanup(&desc->pg_list);
 		return -ENOMEM;
 	}
 	hdr = &whdr->header;