mm/slub: Replace sort_r() with sort() for debugfs stack trace sorting

The comparison function used to sort stack trace locations in debugfs
never relied on the third argument. Therefore, sort_r() is unnecessary.
Switch to sort() with a two-argument comparison function to keep the
code simple and aligned with the intended usage.

Signed-off-by: Kuan-Wei Chiu <[email protected]>
Reviewed-by: Harry Yoo <[email protected]>
Signed-off-by: Vlastimil Babka <[email protected]>

Author: visitorckw

mm/slub.c

@@ -7726,7 +7726,7 @@ static void *slab_debugfs_next(struct seq_file *seq, void *v, loff_t *ppos)
 	return NULL;
 }
 
-static int cmp_loc_by_count(const void *a, const void *b, const void *data)
+static int cmp_loc_by_count(const void *a, const void *b)
 {
 	struct location *loc1 = (struct location *)a;
 	struct location *loc2 = (struct location *)b;
@@ -7793,8 +7793,8 @@ static int slab_debug_trace_open(struct inode *inode, struct file *filep)
 	}
 
 	/* Sort locations by count */
-	sort_r(t->loc, t->count, sizeof(struct location),
-		cmp_loc_by_count, NULL, NULL);
+	sort(t->loc, t->count, sizeof(struct location),
+	     cmp_loc_by_count, NULL);
 
 	bitmap_free(obj_map);
 	return 0;