NFS: Make better use of inode* dereferencing macros

Make better use of inode* dereferencing macros to hide dereferencing chains
(including NFS_PROTO and NFS_CLIENT).

Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 48e8928..a146ed3 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -111,7 +111,7 @@
 
 	nfs_inc_stats(inode, NFSIOS_VFSOPEN);
 	lock_kernel();
-	res = NFS_SERVER(inode)->rpc_ops->file_open(inode, filp);
+	res = NFS_PROTO(inode)->file_open(inode, filp);
 	unlock_kernel();
 	return res;
 }