NFS: Create a common pgio_error function

At this point, the read and write versions of this function look
identical so both should use the same function.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 519864b..a4b9e75 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -242,6 +242,7 @@
 void nfs_rw_header_free(struct nfs_pgio_header *);
 struct nfs_pgio_data *nfs_pgio_data_alloc(struct nfs_pgio_header *, unsigned int);
 void nfs_pgio_data_release(struct nfs_pgio_data *);
+int nfs_pgio_error(struct nfs_pageio_descriptor *, struct nfs_pgio_header *);
 void nfs_pgio_rpcsetup(struct nfs_pgio_data *, unsigned int, unsigned int, int,
 		       struct nfs_commit_info *);