btrfs: drop the _nr from the item helpers

Now that all call sites are using the slot number to modify item values,
rename the SETGET helpers to raw_item_*(), and then rework the _nr()
helpers to be the btrfs_item_*() btrfs_set_item_*() helpers, and then
rename all of the callers to the new helpers.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/props.c b/fs/btrfs/props.c
index b1cb5a8..a978676 100644
--- a/fs/btrfs/props.c
+++ b/fs/btrfs/props.c
@@ -158,7 +158,7 @@ static int iterate_object_props(struct btrfs_root *root,
 
 		di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
 		cur = 0;
-		total_len = btrfs_item_size_nr(leaf, slot);
+		total_len = btrfs_item_size(leaf, slot);
 
 		while (cur < total_len) {
 			u32 name_len = btrfs_dir_name_len(leaf, di);