mm: swap: change swap_alloc_slow() to void

swap_alloc_slow() does not need to return a bool, as all callers handle
allocation results via the entry parameter.  Update the function signature
and remove return statements accordingly.

Link: https://lkml.kernel.org/r/20251031065011.40863-5-youngjun.park@lge.com
Signed-off-by: Youngjun Park <youngjun.park@lge.com>
Reviewed-by: Kairui Song <kasong@tencent.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Acked-by: Chris Li <chrisl@kernel.org>
Cc: Barry Song <baohua@kernel.org>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: youngjuni

mm/swapfile.c

@@ -1339,7 +1339,7 @@ static bool swap_alloc_fast(swp_entry_t *entry,
 }
 
 /* Rotate the device and switch to a new cluster */
-static bool swap_alloc_slow(swp_entry_t *entry,
+static void swap_alloc_slow(swp_entry_t *entry,
 			    int order)
 {
 	unsigned long offset;
@@ -1356,10 +1356,10 @@ static bool swap_alloc_slow(swp_entry_t *entry,
 			put_swap_device(si);
 			if (offset) {
 				*entry = swp_entry(si->type, offset);
-				return true;
+				return;
 			}
 			if (order)
-				return false;
+				return;
 		}
 
 		spin_lock(&swap_avail_lock);
@@ -1378,7 +1378,6 @@ static bool swap_alloc_slow(swp_entry_t *entry,
 			goto start_over;
 	}
 	spin_unlock(&swap_avail_lock);
-	return false;
 }
 
 /*