Wasn't checking the range of the device id in cdio_have_driver. Add regression test for checking this too.

More git administrivia.

test/testdefault.c

@@ -80,6 +80,13 @@ main(int argc, const char *argv[])
   
   cdio_log_set_handler (log_handler);
 
+  if (cdio_have_driver(-1) != false) 
+    {
+      printf("Bogus driver number -1 should be regexted\n");
+      return 5;
+    }
+  
+
   if (! (cdio_have_driver(DRIVER_NRG) && cdio_have_driver(DRIVER_BINCUE)) )  {
     printf("You don't have enough drivers for this test\n");
     exit(77);
@@ -189,12 +196,8 @@ main(int argc, const char *argv[])
   }
     
   cdio_free_device_list(nrg_images);
-  free(nrg_images);
   cdio_free_device_list(bincue_images);
-  free(bincue_images);
   cdio_free_device_list(imgs);
-  free(imgs);
-
   return 0;
   
 }