Remove redundant collectgarbage() calls from scripts

Since 8112d6472e garbage is automatically collected
after running a Lua GUI script.

share/scripts/_dump_latency.lua

@@ -73,5 +73,4 @@ function factory () return function ()
 			lc[1].min, lc[1].max, pcl.min, pcl.max, bcl.min, bcl.max))
 		end
 	end
-	collectgarbage ()
 end end