mm/swap: remove unused local variable nr_shadows

mainline inclusion
from mainline-v5.14-rc1
commit eb7709c5
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I3ZE5V
CVE: NA

-------------------------------------------------

Since commit 55c653b71e8c ("mm: stop accounting shadow entries"),
nr_shadows is not used anymore.

Link: https://lkml.kernel.org/r/20210520134022.1370406-3-linmiaohe@huawei.comSigned-off-by: NMiaohe Lin <linmiaohe@huawei.com>
Reviewed-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NLiu Shixin <liushixin2@huawei.com>
Reviewed-by: NTong Tiangen <tongtiangen@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

mm/swap_state.c

@@ -140,8 +140,6 @@ int add_to_swap_cache(struct page *page, swp_entry_t entry,
 	SetPageSwapCache(page);
 
 	do {
-		unsigned long nr_shadows = 0;
-
 		xas_lock_irq(&xas);
 		xas_create_range(&xas);
 		if (xas_error(&xas))
@@ -150,7 +148,6 @@ int add_to_swap_cache(struct page *page, swp_entry_t entry,
 			VM_BUG_ON_PAGE(xas.xa_index != idx + i, page);
 			old = xas_load(&xas);
 			if (xa_is_value(old)) {
-				nr_shadows++;
 				if (shadowp)
 					*shadowp = old;
 			}
@@ -284,7 +281,6 @@ void clear_shadow_from_swap_cache(int type, unsigned long begin,
 	void *old;
 
 	for (;;) {
-		unsigned long nr_shadows = 0;
 		swp_entry_t entry = swp_entry(type, curr);
 		struct address_space *address_space = swap_address_space(entry);
 		XA_STATE(xas, &address_space->i_pages, curr);
@@ -294,7 +290,6 @@ void clear_shadow_from_swap_cache(int type, unsigned long begin,
 			if (!xa_is_value(old))
 				continue;
 			xas_store(&xas, NULL);
-			nr_shadows++;
 		}
 		xa_unlock_irq(&address_space->i_pages);