fix(match2): wrong table used to call function from on wc3 (#5292)

fix(match2): wrong table used to call function from

components/match2/wikis/warcraft/match_group_input_custom.lua

@@ -484,7 +484,7 @@ function FfaMatchFunctions.matchIsFinished(match, opponents)
 		return true
 	end
 
-	return MatchFunctions.placementHasBeenSet(opponents)
+	return FfaMatchFunctions.placementHasBeenSet(opponents)
 end
 
 ---@param opponents table[]