Replace $HTTP_POST_FILES to $_FILES because the old one is

"deprecated" in new PHP versions.

Perhaps I should have used the upload manager but I'm not really sure
if it's fully available under 14_STABLE and viewing other modules
they use the $_FILES global, so I use such variable here too!

mod/exercise/upload.php

@@ -7,7 +7,7 @@
     require_variable($id);          // course module ID
     $timenow = time();
 
-    $newfile = $HTTP_POST_FILES["newfile"];
+    $newfile = $_FILES["newfile"];
 
     // get some esential stuff...
     if (! $cm = get_record("course_modules", "id", $id)) {

mod/workshop/upload.php

@@ -6,7 +6,7 @@
 
     require_variable($id);          // CM ID
 
-    $newfile = $HTTP_POST_FILES["newfile"];
+    $newfile = $_FILES["newfile"];
 
     if (! $cm = get_record("course_modules", "id", $id)) {
         error("Course Module ID was incorrect");