Update icecream_vat.dm

Missed a spot.

code/modules/food/icecream_vat.dm

@@ -36,6 +36,7 @@
 			return
 		if(!user.drop_item())
 			user << "<span class='warning'>\The [I] is stuck to you!</span>"
+			return
 		beaker = I
 		I.forceMove(src)
 		user << "<span class='notice'>You add [I] to [src]</span>"
@@ -249,4 +250,4 @@
 		dat += show_toppings()
 	var/datum/browser/popup = new(user, "cream_master","Cream-Master Deluxe", 700, 400, src)
 	popup.set_content(dat)
-	popup.open()
+	popup.open()