Fixed the Riot foam icon (#5676)

* Fixed the Riot foam icon

Adds the varable riot to both normal foam darts and adds some else if
statments to give both darts and modified darts the correct icon.

* Update ammo_casings.dm

* Update ammo_casings.dm

* Update ammo_casings.dm

* Fix for single shot stechkin

changes how the stechin updates it's magazine so the single shot
magazine doesn't go invisable.

* Revert "Fix for single shot stechkin"

This reverts commit 11974996c4.

* changed description

changes the discription and moves it one line down.

code/modules/projectiles/ammunition/ammo_casings.dm

@@ -315,10 +315,9 @@
 		if(BB)
 			BB.icon_state = "foamdart_empty"
 	else
-		icon_state = "foamdart"
-		desc = "Its nerf or nothing! Ages 8 and up."
+		icon_state = initial(icon_state)
 		if(BB)
-			BB.icon_state = "foamdart_empty"
+			BB.icon_state = initial(BB.icon_state)
 
 /obj/item/ammo_casing/caseless/foam_dart/attackby(obj/item/A, mob/user, params)
 	..()