More SRM fixes (#30522)

code/game/machinery/machine_frame.dm

@@ -1035,7 +1035,7 @@ to destroy them and players will be able to make replacements.
 /obj/item/circuitboard/salvage_redemption
 	board_name = "Salvage Redemption"
 	icon_state = "supply"
-	build_path = /obj/item/circuitboard/salvage_redemption
+	build_path = /obj/machinery/salvage_redemption
 	board_type = "machine"
 	origin_tech = "programming=1;engineering=2"
 	req_components = list(

code/modules/mining/salvage_redemption.dm

@@ -86,7 +86,7 @@
 
 	if(istype(used, /obj/item/storage/bag/expedition))
 		var/obj/item/storage/bag/expedition/bag = used
-		if(!bag.contents)
+		if(!length(bag.contents))
 			to_chat(user, "<span class='warning'>You have no salvage to redeem.</span>");
 			return ITEM_INTERACT_COMPLETE
 		for(var/obj/item/salvage/loot in bag.contents)