btrfs-progs: Fix a extent buffer leak in count_csum_range().

The commit f495a2ac66 ("btrfs-progs: fsck: remove unfriendly BUG_ON()
for searching tree failure") is causing tons of extent buffer leak if some
csum mismatches in btrfsck.

This is caused by a misplaced btrfs_release_path(), fix it.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>

cmds-check.c

@@ -1186,9 +1186,9 @@ static int count_csum_range(struct btrfs_root *root, u64 start,
 		path.slots[0]++;
 	}
 out:
+	btrfs_release_path(&path);
 	if (ret < 0)
 		return ret;
-	btrfs_release_path(&path);
 	return 0;
 }