Fixed a duplicate variable.

The only effect I noticed was creating asteroid explosions in the
wrong places, but it could be that it had far more disasterous results.

src/alien.cpp

@@ -1051,7 +1051,7 @@ void alien_addSmallAsteroid(object *hostAlien)
 		return;
 
 	int index = -1;
-	int debris = 1 + rand() % 10;
+	int debris = RANDRANGE(1, 10);
 
 	for (int i = 0 ; i < debris ; i++)
 		bullet_add(&weapon[W_ROCKETS], hostAlien, 0, 0);

src/bullet.cpp

@@ -51,24 +51,21 @@ void bullet_add(object *theWeapon, object *attacker, int y, int dy)
 	}
 	else
 	{
-		bullet->dx = (0 - theWeapon->speed);
+		bullet->dx = -theWeapon->speed;
 	}
 
 	if (bullet->flags & WF_VARIABLE_SPEED)
 	{
-		bullet->dx = RANDRANGE(100, 200);
-		bullet->dx /= 10;
+		bullet->dx = RANDRANGE(100, 200) / 10;
 		if (attacker->face == 1)
-			bullet->dx = 0 - bullet->dx;
+			bullet->dx = -bullet->dx;
 	}
 
 	bullet->dy = dy;
 
 	if (bullet->flags & WF_SCATTER)
 	{
-		bullet->dy = RANDRANGE(-200, 200);
-		if (bullet->dy != 0)
-			bullet->dy /= 200;
+		bullet->dy = RANDRANGE(-200, 200) / 200;
 	}
 
 	if (attacker->flags & FL_WEAPCO)

src/game.cpp

@@ -1007,8 +1007,10 @@ static void game_doAliens()
 					if (aliens[i].classDef == CD_ASTEROID)
 					{
 						n = 1 + (rand() % 3);
-						for (int i = 0 ; i < n ; i++)
+						for (int j = 0 ; j < n ; j++)
+						{
 							alien_addSmallAsteroid(&aliens[i]);
+						}
 					}
 				}
 			}