libsparse: add error reporting functions

Change-Id: I2f21355b6c5339d1d724b4c121ea30d575b2d366
diff --git a/libsparse/sparse.c b/libsparse/sparse.c
index 4ebcf0f..3403604 100644
--- a/libsparse/sparse.c
+++ b/libsparse/sparse.c
@@ -151,3 +151,8 @@
 
 	return 0;
 }
+
+void sparse_file_verbose(struct sparse_file *s)
+{
+	s->verbose = true;
+}