message: fix bug in Matx::inv()
diff: @@ -194,8 +194,8 @@ Matx<_Tp, n, m> Matx<_Tp, m, n>::inv(int method, bool *p_is_ok /*= NULL*/) const
  {
  Matx<_Tp, n, m> b;
  bool ok;
  - if( method == DECOMP_LU || method == DECOMP_CHOLESKY )
  - ok = cv::internal::Matx_FastInvOp<_Tp, m>()(*this, b, method);
  + if( m == n && (method == DECOMP_LU || method == DECOMP_CHOLESKY) )
  + ok = cv::internal::Matx_FastInvOp<_Tp, m>()(*reinterpret_cast<const Matx<_Tp, m, m>*>(this), reinterpret_cast<Matx<_Tp, m, m>&>(b), method);
  else
  {
  Mat A(*this, false), B(b, false);
  