Lua 5.2 upgrade [1] for NSE.

[1] http://seclists.org/nmap-dev/2012/q2/34

scripts/broadcast-netbios-master-browser.nse

@@ -1,3 +1,9 @@
+local bit = require "bit"
+local netbios = require "netbios"
+local nmap = require "nmap"
+local stdnse = require "stdnse"
+local tab = require "tab"
+
 description = [[
 Attempts to discover master browsers and the domains they manage.
 ]]
@@ -19,9 +25,6 @@ author = "Patrik Karlsson"
 license = "Same as Nmap--See http://nmap.org/book/man-legal.html"
 categories = {"broadcast", "safe"}
 
-require 'netbios'
-require 'tab'
-require 'bit'
 
 prerule = function() return true end
 
@@ -62,4 +65,4 @@ action = function()
 		end
 	end
 	return "\n" .. tab.dump(outtab)
-end
+end