eth/protocols/snap: optimize incHash (#32748)

Author: cuiweixie

eth/protocols/snap/range.go

@@ -74,8 +74,11 @@ func (r *hashRange) End() common.Hash {
 
 // incHash returns the next hash, in lexicographical order (a.k.a plus one)
 func incHash(h common.Hash) common.Hash {
-	var a uint256.Int
-	a.SetBytes32(h[:])
-	a.AddUint64(&a, 1)
-	return common.Hash(a.Bytes32())
+	for i := len(h) - 1; i >= 0; i-- {
+		h[i]++
+		if h[i] != 0 {
+			break
+		}
+	}
+	return h
 }