Convert file descriptors to generic streams

src/kernel/keyboard.c

@@ -76,7 +76,10 @@ static uint64_t stream_read(__attribute__((unused)) const stream_t *self, uint64
   return size;
 }
 
-static stream_t stream = {stream_write, stream_read};
+static void stream_close(__attribute__((unused)) stream_t *self) {
+}
+
+static stream_t stream = {stream_write, stream_read, stream_close};
 
 static void on_key(uint8_t scancode) {
   const uint8_t pressed = !(scancode & 0x80);