btrfs: reorder btrfs_trans_handle members for better packing

Recent updates to the structure left some holes, reorder the types so
the packing is tight. The size goes from 112 to 104 on 64bit.
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/transaction.h

@@ -111,11 +111,12 @@ struct btrfs_trans_handle {
 	u64 transid;
 	u64 bytes_reserved;
 	u64 chunk_bytes_reserved;
-	refcount_t use_count;
 	unsigned long delayed_ref_updates;
 	struct btrfs_transaction *transaction;
 	struct btrfs_block_rsv *block_rsv;
 	struct btrfs_block_rsv *orig_rsv;
+	refcount_t use_count;
+	unsigned int type;
 	short aborted;
 	bool adding_csums;
 	bool allocating_chunk;
@@ -123,7 +124,6 @@ struct btrfs_trans_handle {
 	bool reloc_reserved;
 	bool sync;
 	bool dirty;
-	unsigned int type;
 	struct btrfs_root *root;
 	struct btrfs_fs_info *fs_info;
 	struct list_head new_bgs;