btrfs-tree: accessors for TreeFetcher classes' type and tree values

Sometimes we have a generic TreeFetcher and we need to know which tree
it came from.

Signed-off-by: Zygo Blaxell <bees@furryterror.org>

lib/btrfs-tree.cc

@@ -283,12 +283,24 @@ namespace crucible {
 		m_type = type;
 	}
 
+	uint8_t
+	BtrfsTreeFetcher::type()
+	{
+		return m_type;
+	}
+
 	void
 	BtrfsTreeFetcher::tree(uint64_t tree)
 	{
 		m_tree = tree;
 	}
 
+	uint64_t
+	BtrfsTreeFetcher::tree()
+	{
+		return m_tree;
+	}
+
 	void
 	BtrfsTreeFetcher::transid(uint64_t min_transid, uint64_t max_transid)
 	{