Fixed global assignments with nse_check_globals

All fixes made by hand. A couple real bugs/errors fixed, due to
copy-paste of code from other scripts without changing variable names.

scripts/http-fileupload-exploiter.nse

@@ -55,6 +55,7 @@ author = "George Chatzisofroniou"
 license = "Same as Nmap--See http://nmap.org/book/man-legal.html"
 
 local http = require "http"
+local io = require "io"
 local string = require "string"
 local httpspider = require "httpspider"
 local shortport = require "shortport"
@@ -106,7 +107,7 @@ local function UploadRequest(host, port, submission, partofrequest, name, filena
         success = 0;
 
         make = function(self)
-            options = { header={} }
+            local options = { header={} }
             options['header']['Content-Type'] = "multipart/form-data; boundary=AaB03x"
             options['content'] = self.partofrequest .. '--AaB03x\nContent-Disposition: form-data; name="' .. self.name .. '"; filename="' .. self.filename .. '"\nContent-Type: ' .. self.mime .. '\n\n' .. self.payload .. '\n--AaB03x--'
  
@@ -119,7 +120,7 @@ local function UploadRequest(host, port, submission, partofrequest, name, filena
 
         checkPayload = function(self, uploadspaths)
             for _, uploadpath in ipairs(uploadspaths) do
-                response = http.get(host, port, uploadpath .. '/' .. filename, { no_cache = true } )
+                local response = http.get(host, port, uploadpath .. '/' .. filename, { no_cache = true } )
  
                 if response.status ~= 404 then
                     if (response.body:match(self.check)) then
@@ -260,6 +261,7 @@ action = function(host, port)
                     local action_absolute = string.find(form["action"], "https*://")
               
                     -- Determine the path where the form needs to be submitted.
+                    local submission
                     if action_absolute then
                         submission = form["action"]
                     else    
@@ -270,7 +272,7 @@ action = function(host, port)
 
                     foundform = 1
 
-                    partofrequest, filefield = prepareRequest(form["fields"], fieldvalues)
+                    local partofrequest, filefield = prepareRequest(form["fields"], fieldvalues)
 
                     if filefield ~= 0 then