native: more accurate comment about lwork in Dorgtr
@@ -18,7 +18,7 @@ import "github.com/gonum/blas"
// tau must have length at least n-1, and Dorgtr will panic otherwise.
//
// work is temporary storage, and lwork specifies the usable memory length. At
-// minimum, lwork >= n-1, and Dorgtr will panic otherwise. The amount of blocking
+// minimum, lwork >= max(1,n-1), and Dorgtr will panic otherwise. The amount of blocking
// is limited by the usable length.
// If lwork == -1, instead of computing Dorgtr the optimal work length is stored
// into work[0].
