fix memory error in test for n_sizeinbase
fix memory error in test for n_sizeinbase

jpflori/flint2,dsroche/flint2,jpflori/flint2,fredrik-johansson/flint2,jpflori/flint2,dsroche/flint2,jpflori/flint2,dsroche/flint2,fredrik-johansson/flint2,wbhart/flint2,wbhart/flint2,wbhart/flint2,fredrik-johansson/flint2,dsroche/flint2