usb: sierra: fix a missing check of device_create_file

device_create_file() could fail and return an error code. The fix
captures the error and returns the error code upstream in case it
indeed failed.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/storage/sierra_ms.c

@@ -194,8 +194,6 @@ int sierra_ms_init(struct us_data *us)
 		kfree(swocInfo);
 	}
 complete:
-	result = device_create_file(&us->pusb_intf->dev, &dev_attr_truinst);
-
-	return 0;
+	return device_create_file(&us->pusb_intf->dev, &dev_attr_truinst);
 }