Fix typo in tradehelpers

Author: vaisest

src/Classes/TradeHelpers.lua

@@ -406,7 +406,7 @@ function M.buildModMap(item)
 end
 
 -- Helper: get diff label string for an item slot comparison
---- @param pIem table
+--- @param pItem table
 --- @param cItem table
 function M.getSlotDiffLabel(pItem, cItem)
 	if not pItem and not cItem then