btrfs: remove extent_buffer::recursed

It is unused everywhere now, it can be removed.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/extent_io.c

@@ -4966,7 +4966,6 @@ __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start,
 	eb->fs_info = fs_info;
 	eb->bflags = 0;
 	init_rwsem(&eb->lock);
-	eb->lock_recursed = false;
 
 	btrfs_leak_debug_add(&fs_info->eb_leak_lock, &eb->leak_list,
 			     &fs_info->allocated_ebs);

fs/btrfs/extent_io.h

@@ -87,7 +87,6 @@ struct extent_buffer {
 	int read_mirror;
 	struct rcu_head rcu_head;
 	pid_t lock_owner;
-	bool lock_recursed;
 	/* >= 0 if eb belongs to a log tree, -1 otherwise */
 	s8 log_index;