crypto/bn256: fix go vet false positive

Also add the package to the license tool ignore list.

1 files changed, 4 insertions, 4 deletions

diff --git a/crypto/bn256/twist.go b/crypto/bn256/twist.go
index 1e052456e..95b966e2e 100644
--- a/crypto/bn256/twist.go
+++ b/crypto/bn256/twist.go
@@ -165,12 +165,12 @@ func (c *twistPoint) Double(a *twistPoint, pool *bnPool) {
 	// See http://hyperelliptic.org/EFD/g1p/auto-code/shortw/jacobian-0/doubling/dbl-2009-l.op3
 	A := newGFp2(pool).Square(a.x, pool)
 	B := newGFp2(pool).Square(a.y, pool)
-	C := newGFp2(pool).Square(B, pool)
+	C_ := newGFp2(pool).Square(B, pool)
 
 	t := newGFp2(pool).Add(a.x, B)
 	t2 := newGFp2(pool).Square(t, pool)
 	t.Sub(t2, A)
-	t2.Sub(t, C)
+	t2.Sub(t, C_)
 	d := newGFp2(pool).Add(t2, t2)
 	t.Add(A, A)
 	e := newGFp2(pool).Add(t, A)
@@ -179,7 +179,7 @@ func (c *twistPoint) Double(a *twistPoint, pool *bnPool) {
 	t.Add(d, d)
 	c.x.Sub(f, t)
 
-	t.Add(C, C)
+	t.Add(C_, C_)
 	t2.Add(t, t)
 	t.Add(t2, t2)
 	c.y.Sub(d, c.x)
@@ -191,7 +191,7 @@ func (c *twistPoint) Double(a *twistPoint, pool *bnPool) {
 
 	A.Put(pool)
 	B.Put(pool)
-	C.Put(pool)
+	C_.Put(pool)
 	t.Put(pool)
 	t2.Put(pool)
 	d.Put(pool)