Replaces "istype"s with is_helpers macros (#28676)

code/game/objects/structures/crates_lockers/closets.dm

@@ -276,7 +276,7 @@
 	var/actuallyismob = 0
 	if(isliving(O))
 		actuallyismob = 1
-	else if(!istype(O, /obj/item))
+	else if(!isitem(O))
 		return
 	var/turf/T = get_turf(src)
 	var/list/targets = list(O, src)
@@ -355,7 +355,7 @@
 /obj/structure/closet/container_resist(mob/living/user)
 	if(opened)
 		return
-	if(istype(loc, /atom/movable))
+	if(ismovableatom(loc))
 		user.changeNext_move(CLICK_CD_BREAKOUT)
 		user.last_special = world.time + CLICK_CD_BREAKOUT
 		var/atom/movable/AM = loc

code/game/objects/structures/morgue.dm

@@ -276,7 +276,7 @@ GLOBAL_LIST_EMPTY(crematoriums)
 		to_chat(user, "<span class='warning'>That's not connected to anything!</span>")
 
 /obj/structure/tray/MouseDrop_T(atom/movable/O as mob|obj, mob/user)
-	if(!istype(O, /atom/movable) || O.anchored || !Adjacent(user) || !user.Adjacent(O) || O.loc == user)
+	if(!ismovableatom(O) || O.anchored || !Adjacent(user) || !user.Adjacent(O) || O.loc == user)
 		return
 	if(!ismob(O))
 		if(!istype(O, /obj/structure/closet/body_bag))

code/game/objects/structures/watercloset.dm

@@ -289,7 +289,7 @@
 /obj/machinery/shower/proc/wash_obj(atom/movable/O)
 	O.clean_blood()
 
-	if(istype(O,/obj/item))
+	if(isitem(O))
 		var/obj/item/I = O
 		I.acid_level = 0
 		I.extinguish()