nilfs2: Use xa_erase_irq

This code simply opencoded xa_erase_irq().

Signed-off-by: Matthew Wilcox <[e-mail]>

fs/nilfs2/btnode.c

···
 		return;
 
 	if (nbh == NULL) {	/* blocksize == pagesize */
-		xa_lock_irq(&btnc->i_pages);
-		__xa_erase(&btnc->i_pages, newkey);
-		xa_unlock_irq(&btnc->i_pages);
+		xa_erase_irq(&btnc->i_pages, newkey);
 		unlock_page(ctxt->bh->b_page);
 	} else
 		brelse(nbh);