Clean up check for item being equipped

Moved some common code to item.dm. Someone should probably take a look
at get_equipped_items() in inventory.dm sometime in the future.

code/modules/clothing/spacesuits/alien.dm

@@ -155,17 +155,6 @@
 	species_restricted = list("Vox")
 	action_button_name = "Toggle the magclaws"
 
-//make sure these can only be used when equipped.
-/obj/item/clothing/shoes/magboots/vox/proc/can_use()
-	if(!ismob(loc)) 
-		return 0
-	
-	var/mob/M = loc
-	if(src in M.get_equipped_items())
-		return 1
-	else
-		return 0
-
 /obj/item/clothing/shoes/magboots/vox/attack_self(mob/user)
 	if(src.magpulse)
 		flags &= ~NOSLIP
@@ -173,7 +162,8 @@
 		canremove = 1
 		user << "You relax your deathgrip on the flooring."
 	else
-		if (!can_use())
+		//make sure these can only be used when equipped.
+		if (!is_equipped())
 			user << "You will have to put on the [src] before you can do that."
 			return
 		
@@ -185,6 +175,7 @@
 
 //In case they somehow come off while enabled.
 /obj/item/clothing/shoes/magboots/vox/dropped(mob/user as mob)
+	..()
 	if(src.magpulse)
 		user.visible_message("The [src] go limp as they are removed from [usr]'s feet.", "The [src] go limp as they are removed from your feet.")
 		flags &= ~NOSLIP