Fixes door projectile damage

Not only does it not make much sense that projectiles do 4x as much damage to doors, it also makes it very easy to bust through multiple doors with a laser gun.

Removing the multiplier now makes it so that deciding to use your gun to break a door has a real cost, eating up a good portion of the clip.

Weapon | Number of Shot to Break
------------|----------------------------------
C20r SMG | 15
Laser Carbine | 8
Shotgun | 5
Laser Cannon | 4

Also fixes the return before parent call in bullet_act().