iwlwifi: print warning on request_module failure

If request_module() failed then we didn't have the correct
opmode module that the driver needs to function, so print
a warning in this case to make it more obvious what could
be wrong. This still won't catch the case where the module
simply doesn't exist because it wasn't compiled though.
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/iwlwifi/iwl-drv.c

@@ -998,8 +998,13 @@ static void iwl_req_fw_callback(const struct firmware *ucode_raw, void *context)
 	 * else from proceeding if the module fails to load
 	 * or hangs loading.
 	 */
-	if (load_module)
-		request_module("%s", op->name);
+	if (load_module) {
+		err = request_module("%s", op->name);
+		if (err)
+			IWL_ERR(drv,
+				"failed to load module %s (error %d), is dynamic loading enabled?\n",
+				op->name, err);
+	}
 	return;
 
  try_again: