mm/swap: remove unneeded return value of free_swap_slot

The return value of free_swap_slot is always 0 and also ignored now. 
Remove it to clean up the code.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Miaohe Lin <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Reviewed-by: Oscar Salvador <[email protected]>
Cc: Alistair Popple <[email protected]>
Cc: David Howells <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: NeilBrown <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

2 files changed, 2 insertions, 4 deletions

diff --git a/include/linux/swap_slots.h b/include/linux/swap_slots.h
index 347f1a304190..15adfb8c813a 100644
--- a/include/linux/swap_slots.h
+++ b/include/linux/swap_slots.h
@@ -24,7 +24,7 @@ struct swap_slots_cache {
 void disable_swap_slots_cache_lock(void);
 void reenable_swap_slots_cache_unlock(void);
 void enable_swap_slots_cache(void);
-int free_swap_slot(swp_entry_t entry);
+void free_swap_slot(swp_entry_t entry);
 
 extern bool swap_slot_cache_enabled;
 
diff --git a/mm/swap_slots.c b/mm/swap_slots.c
index 0218ec1cd24c..2f877e6f87d7 100644
--- a/mm/swap_slots.c
+++ b/mm/swap_slots.c
@@ -269,7 +269,7 @@ static int refill_swap_slots_cache(struct swap_slots_cache *cache)
 	return cache->nr;
 }
 
-int free_swap_slot(swp_entry_t entry)
+void free_swap_slot(swp_entry_t entry)
 {
 	struct swap_slots_cache *cache;
 
@@ -297,8 +297,6 @@ int free_swap_slot(swp_entry_t entry)
 direct_free:
 		swapcache_free_entries(&entry, 1);
 	}
-
-	return 0;
 }
 
 swp_entry_t folio_alloc_swap(struct folio *folio)