btrfs: kill the key type accessor helpers

btrfs_set_key_type and btrfs_key_type are used inconsistently along with
open coded variants. Other members of btrfs_key are accessed directly
without any helpers anyway.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 54a201d..cfe8566 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -1193,7 +1193,7 @@
 	unsigned long ptr;
 
 	key.objectid = inode_objectid;
-	btrfs_set_key_type(&key, BTRFS_INODE_EXTREF_KEY);
+	key.type = BTRFS_INODE_EXTREF_KEY;
 	key.offset = start_off;
 
 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
@@ -1233,7 +1233,7 @@
 		ret = -ENOENT;
 		if (found_key.objectid != inode_objectid)
 			break;
-		if (btrfs_key_type(&found_key) != BTRFS_INODE_EXTREF_KEY)
+		if (found_key.type != BTRFS_INODE_EXTREF_KEY)
 			break;
 
 		ret = 0;