scd: Minor fix for readibility.

* scd/command.c (open_card_with_request): Use NULL instead of
APPTYPE_NULL.
--

Using the enum is wrong because a string is expected.  However it did
harm anything because the value of the enum is 0 and thus equivalent
to NULL.

Signed-off-by: Werner Koch <wk@gnupg.org>

g10/skclist.c

@@ -293,7 +293,7 @@ build_sk_list (ctrl_t ctrl,
  * --default-key and --try-secret-key).  Use the following procedure:
  *
  *  1) Initialize a void pointer to NULL
- *  2) Pass a reference to this pointer to this function (content)
+ *  2) Pass a reference to this pointer to this function (context)
  *     and provide space for the secret key (sk)
  *  3) Call this function as long as it does not return an error (or
  *     until you are done).  The error code GPG_ERR_EOF indicates the

scd/app.c

@@ -788,7 +788,7 @@ select_additional_application_internal (card_t card, apptype_t req_apptype)
 
 
 /* Add all possible additional applications to the card context but do
- * not change the current one.  This current works only for Yubikeys. */
+ * not change the current one.  This currently works only for Yubikeys. */
 static gpg_error_t
 select_all_additional_applications_internal (card_t card)
 {

scd/command.c

@@ -263,7 +263,7 @@ open_card_with_request (ctrl_t ctrl,
   err = select_application (ctrl, apptypestr, &ctrl->card_ctx, 1,
                             serialno_bin, serialno_bin_len);
   if (!err && opt_all)
-    err = select_additional_application (ctrl, APPTYPE_NONE);
+    err = select_additional_application (ctrl, NULL);
 
  leave:
   xfree (serialno_bin);