format code with black

Before, this argument was ignored.  This prevented adafruit_sdcard from
functioning, as it relies on being able to send out the value 0xff.

This fix is speculative and untested.

src/adafruit_blinka/microcontroller/ft232h/spi.py

@@ -67,7 +67,8 @@ class SPI:
     def readinto(self, buf, start=0, end=None, write_value=0):
         """Read data from SPI and into the buffer"""
         end = end if end else len(buf)
-        result = self._port.read(end - start)
+        buffer_out = [write_value] * (end - start)
+        result = self._port.exchange(buffer_out, end - start, duplex=True)
         for i, b in enumerate(result):
             buf[start + i] = b
 

src/adafruit_blinka/microcontroller/nxp_lpc4330/spi.py

@@ -93,7 +93,7 @@ class SPI:
     def readinto(self, buf, start=0, end=None, write_value=0):
         """Read data from SPI and into the buffer"""
         end = end if end else len(buf)
-        result = self._transmit([], end - start)
+        result = self._transmit([write_value] * (end - start), end - start)
         for i, b in enumerate(result):
             buf[start + i] = b