Small changes to nmod_poly_xgcd_euclidean
Small changes to nmod_poly_xgcd_euclidean

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