优化几个unpack调用

Zframework/scene.lua

@@ -137,7 +137,8 @@ function SCN.swapTo(tar,style)--Parallel scene swapping, cannot back
 			SCN.swapping=true
 			local S=SCN.stat
 			S.tar,S.style=tar,style
-			S.time,S.mid,S.draw=unpack(swap[style])
+			local s=swap[style]
+			S.time,S.mid,S.draw=s[1],s[2],s[3]
 		end
 	else
 		LOG.print("No Scene: "..tar,"warn")