maple_tree: relocate the declaration of mas_empty_area_rev().

Relocate the declaration of mas_empty_area_rev() so that mas_empty_area()
and mas_empty_area_rev() are together.

Link: https://lkml.kernel.org/r/20230524031247.65949-11-zhangpeng.00@bytedance.comSigned-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/linux/maple_tree.h

@@ -474,6 +474,12 @@ void *mas_next_range(struct ma_state *mas, unsigned long max);
 
 int mas_empty_area(struct ma_state *mas, unsigned long min, unsigned long max,
 		   unsigned long size);
+/*
+ * This finds an empty area from the highest address to the lowest.
+ * AKA "Topdown" version,
+ */
+int mas_empty_area_rev(struct ma_state *mas, unsigned long min,
+		       unsigned long max, unsigned long size);
 
 static inline void mas_init(struct ma_state *mas, struct maple_tree *tree,
 			    unsigned long addr)
@@ -497,12 +503,6 @@ static inline bool mas_is_paused(const struct ma_state *mas)
 	return mas->node == MAS_PAUSE;
 }
 
-/*
- * This finds an empty area from the highest address to the lowest.
- * AKA "Topdown" version,
- */
-int mas_empty_area_rev(struct ma_state *mas, unsigned long min,
-		       unsigned long max, unsigned long size);
 /**
  * mas_reset() - Reset a Maple Tree operation state.
  * @mas: Maple Tree operation state.