LUA: remove duplicate words

Change-Id: Id3c5b1d7f67d8e4d3149ed6bdee7307bf13fda3d
Reviewed-on: https://code.wireshark.org/review/36263
Petri-Dish: Anders Broman <a.broman58@gmail.com>
Reviewed-by: Alexis La Goutte <alexis.lagoutte@gmail.com>
Tested-by: Petri Dish Buildbot
Reviewed-by: Stig Bjørlykke <stig@bjorlykke.org>

epan/wslua/init_wslua.c

@@ -528,7 +528,7 @@ static gboolean lua_load_script(const gchar* filename, const gchar* dirname, con
     lua_settop(L,0);
 
     lua_pushcfunction(L, error_handler_with_callback);
-    /* The source argument should start with with '@' to indicate a file. */
+    /* The source argument should start with '@' to indicate a file. */
     lua_pushfstring(L, "@%s", filename);
 
 #if LUA_VERSION_NUM >= 502

epan/wslua/wslua_field.c

@@ -510,7 +510,7 @@ WSLUA_FUNCTION wslua_all_field_infos(lua_State* L) {
 
 WSLUA_CLASS_DEFINE(Field,FAIL_ON_NULL("Field"));
 /*
-   A Field extractor to to obtain field values. A `Field` object can only be created *outside* of
+   A Field extractor to obtain field values. A `Field` object can only be created *outside* of
    the callback functions of dissectors, post-dissectors, heuristic-dissectors, and taps.
 
    Once created, it is used *inside* the callback functions, to generate a `FieldInfo` object.

epan/wslua/wslua_util.c

@@ -12,7 +12,7 @@
 
 #include "config.h"
 
-/* WSLUA_MODULE Utility Utility Functions */
+/* WSLUA_MODULE Utility Functions */
 
 #include "wslua.h"
 #include <math.h>