btrfs: switch BTRFS_ROOT_* to enums

/*

 * The state of btrfs root

 */

enum {

	/*

 * btrfs_record_root_in_trans is a multi-step process,

 * and it can race with the balancing code.   But the

 * race is very small, and only the first time the root

 * is added to each transaction.  So IN_TRANS_SETUP

	 * btrfs_record_root_in_trans is a multi-step process, and it can race

	 * with the balancing code.   But the race is very small, and only the

	 * first time the root is added to each transaction.  So IN_TRANS_SETUP

	 * is used to tell us when more checks are required

	 */

#define BTRFS_ROOT_IN_TRANS_SETUP	0

#define BTRFS_ROOT_REF_COWS		1

#define BTRFS_ROOT_TRACK_DIRTY		2

#define BTRFS_ROOT_IN_RADIX		3

#define BTRFS_ROOT_ORPHAN_ITEM_INSERTED	4

#define BTRFS_ROOT_DEFRAG_RUNNING	5

#define BTRFS_ROOT_FORCE_COW		6

#define BTRFS_ROOT_MULTI_LOG_TASKS	7

#define BTRFS_ROOT_DIRTY		8

	BTRFS_ROOT_IN_TRANS_SETUP,

	BTRFS_ROOT_REF_COWS,

	BTRFS_ROOT_TRACK_DIRTY,

	BTRFS_ROOT_IN_RADIX,

	BTRFS_ROOT_ORPHAN_ITEM_INSERTED,

	BTRFS_ROOT_DEFRAG_RUNNING,

	BTRFS_ROOT_FORCE_COW,

	BTRFS_ROOT_MULTI_LOG_TASKS,

	BTRFS_ROOT_DIRTY,

};

/*

 * in ram representation of the tree.  extent_root is used for all allocations