Input: evdev - if no events and non-block, return EAGAIN not 0

Signed-off-by: NDima Zavin <dima@android.com>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

drivers/input/evdev.c

@@ -412,6 +412,9 @@ static ssize_t evdev_read(struct file *file, char __user *buffer,
 		retval += input_event_size();
 	}
 
+	if (retval == 0 && (file->f_flags & O_NONBLOCK))
+		return -EAGAIN;
+
 	return retval;
 }