message: Fix some lint warnings in PrimitiveSet.java
diff: @@ -362,12 +362,14 @@ public final class PrimitiveSet<P> {
  }
  /* Adds a non-primary primitive.*/
  + @CanIgnoreReturnValue
  public Builder<P> addPrimitive(final P primitive, Keyset.Key key)
  throws GeneralSecurityException {
  return addPrimitive(primitive, key, false);
  }
  /* Adds the primary primitive. Should be called exactly once per PrimitiveSet.*/
  + @CanIgnoreReturnValue
  public Builder<P> addPrimaryPrimitive(final P primitive, Keyset.Key key)
  throws GeneralSecurityException {
  return addPrimitive(primitive, key, true);
  