NFS: Proper accounting for NFS VFS calls

Nit: The VFSOPEN and VFSFLUSH counters are function call counters.
Count every call to these routines.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/file.c

@@ -123,11 +123,11 @@ nfs_file_open(struct inode *inode, struct file *filp)
 			filp->f_path.dentry->d_parent->d_name.name,
 			filp->f_path.dentry->d_name.name);
 
+	nfs_inc_stats(inode, NFSIOS_VFSOPEN);
 	res = nfs_check_flags(filp->f_flags);
 	if (res)
 		return res;
 
-	nfs_inc_stats(inode, NFSIOS_VFSOPEN);
 	res = nfs_open(inode, filp);
 	return res;
 }
@@ -237,9 +237,9 @@ nfs_file_flush(struct file *file, fl_owner_t id)
 			dentry->d_parent->d_name.name,
 			dentry->d_name.name);
 
+	nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
 	if ((file->f_mode & FMODE_WRITE) == 0)
 		return 0;
-	nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
 
 	/* Flush writes to the server and return any errors */
 	return nfs_do_fsync(ctx, inode);