ShiftRegisterKeys key_count value was wrong

[dhalbert]

• Fixes keypad.ShiftRegisterKeys has wrong key_count #9718

When keypad.ShiftRegisterKeys(..., key_count=some_integer, ...) had an integer argument, the argument was not correctly converted to an integer. This error was inadvertently introduced by #8143.

Testing:

import board
import keypad

keys = keypad.ShiftRegisterKeys(
    data               = board.GP0,
   clock              = board.GP1,
   latch              = board.GP2,
   key_count          = 8,
   value_when_pressed = True,
   value_to_latch     = True,
   )

The bug is that .u_int was used instead of .u_obj. When the bug is present, keys.key_count produces 17 (which is the encoded micropython representation of 8). This fix returns 8 correctly.

[dhalbert]

@aseanwatson, the reporter in #9718, has tested and confirms it's a fix.

[jepler]

thank you!