message: Fix overflowing multiplication
diff: @@ -40,7 +40,7 @@ fn insert_and_remove(xs: Vec<i32>, inserts_each: u8) -> StorageHashMap<i32, i32>
  if x % 2 == 0 {
  // On even numbers we insert
  for key in x..x + inserts_each {
  - let val = key * 10;
  + let val = key.saturating_mul(10);
  if map.insert(key, val).is_none() {
  assert_eq!(map.get(&key), Some(&val));
  cnt_inserts += 1;
  @@ -61,7 +61,7 @@ fn insert_and_remove(xs: Vec<i32>, inserts_each: u8) -> StorageHashMap<i32, i32>
  // items.
  let x = previous_even_x.unwrap();
  for key in x..x + inserts_each {
  - let val = key * 10;
  + let val = key.saturating_mul(10);
  assert_eq!(map.get(&key), Some(&val));
  assert_eq!(map.take(&key), Some(val));
  assert_eq!(map.get(&key), None);
  @@ -100,7 +100,7 @@ fn fuzz_removes(xs: Vec<i32>, xth: usize) {
  let i = xs.get(x).expect(
  "x is always in bounds since we iterate over the vec length; qed",
  );
  - assert_eq!(map.insert(*i, i * 10), None);
  + assert_eq!(map.insert(*i, i.saturating_mul(10)), None);
  len += 1;
  assert_eq!(map.len(), len);
  }
  @@ -111,7 +111,7 @@ fn fuzz_removes(xs: Vec<i32>, xth: usize) {
  let i = xs.get(x).expect(
  "x is always in bounds since we iterate over the vec length; qed",
  );
  - assert_eq!(map.take(&i), Some(i * 10));
  + assert_eq!(map.take(&i), Some(i.saturating_mul(10)));
  len -= 1;
  }
  assert_eq!(map.len(), len);
  @@ -124,7 +124,7 @@ fn fuzz_removes(xs: Vec<i32>, xth: usize) {
  let i = xs.get(x).expect(
  "x is always in bounds since we iterate over the vec length; qed",
  );
  - assert_eq!(map.get(&i), Some(&(i * 10)));
  + assert_eq!(map.get(&i), Some(&(i.saturating_mul(10))));
  }
  }
  