To avoid bloating SPL code, use debug() where possible in the driver model
core code. The error code is already returned, and can be investigated as
needed.
Signed-off-by: Simon Glass <sjg@chromium.org>
 
        drv = lists_driver_lookup_name(drv_name);
        if (!drv) {
-               printf("Cannot find driver '%s'\n", drv_name);
+               debug("Cannot find driver '%s'\n", drv_name);
                return -ENOENT;
        }
        ret = device_bind(parent, drv, dev_name, NULL, node, devp);
        if (ret) {
-               printf("Cannot create device named '%s' (err=%d)\n",
-                      dev_name, ret);
+               debug("Cannot create device named '%s' (err=%d)\n",
+                     dev_name, ret);
                return ret;
        }