kbx: Fix allocation check

* kbx/kbxserver.c (cmd_search): Fix allocation check
--

GnuPG-bug-id: 5393
Signed-off-by: Jakub Jelen <jjelen@redhat.com>

kbx/kbxserver.c

@@ -391,7 +391,7 @@ cmd_search (assuan_context_t ctx, char *line)
               goto leave;
             }
           store = xtrycalloc (n, sizeof *store);
-          if (!desc)
+          if (!store)
             {
               err = gpg_error_from_syserror ();
               xfree (desc);