[PATCH V2] Btrfs-progs: fix compile warning in btrfs_free_block_groups()

[Wang Shilong <wangshilong1991@gmail.com>]

From: Wang Shilong <wangsl-fnst@cn.fujitsu.com>

extent-tree.c: In function 'btrfs_free_block_groups':
extent-tree.c:3189:12: warning: cast to pointer from
integer of different size [-Wint-to-pointer-cast]

Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
---
V1->V2: use 'uintptr_t' instead of 'unsigned long'(Thanks Stefan)
---
 extent-tree.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/extent-tree.c b/extent-tree.c
index f597e16..494cf21 100644
--- a/extent-tree.c
+++ b/extent-tree.c
@@ -18,6 +18,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <stdint.h>
 #include "kerncompat.h"
 #include "radix-tree.h"
 #include "ctree.h"
@@ -3180,7 +3181,8 @@ int btrfs_free_block_groups(struct btrfs_fs_info *info)
 			break;
 		ret = get_state_private(&info->block_group_cache, start, &ptr);
 		if (!ret) {
-			cache = (struct btrfs_block_group_cache *)ptr;
+			cache = (struct btrfs_block_group_cache *)
+				(uintptr_t)ptr;
 			if (cache->free_space_ctl) {
 				btrfs_remove_free_space_cache(cache);
 				kfree(cache->free_space_ctl);
-- 
1.7.11.7