fix indent size.

Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/swap_state.c

@@ -92,12 +92,12 @@ static int __add_to_swap_cache(struct page *page, swp_entry_t entry)
 	spin_unlock_irq(&swapper_space.tree_lock);
 
 	if (unlikely(error)) {
-			/*
-			 * Only the context which have set SWAP_HAS_CACHE flag
-			 * would call add_to_swap_cache().
-			 * So add_to_swap_cache() doesn't returns -EEXIST.
-			 */
-			VM_BUG_ON(error == -EEXIST);
+		/*
+		 * Only the context which have set SWAP_HAS_CACHE flag
+		 * would call add_to_swap_cache().
+		 * So add_to_swap_cache() doesn't returns -EEXIST.
+		 */
+		VM_BUG_ON(error == -EEXIST);
 		set_page_private(page, 0UL);
 		ClearPageSwapCache(page);
 		page_cache_release(page);