hw/i8042: Fix value uninitialized in kbd_io()

  GCC Version:
    gcc (GCC) 8.4.1 20200928 (Red Hat 8.4.1-1)

  hw/i8042.c: In function ‘kbd_io’:
  hw/i8042.c:153:19: error: ‘value’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
     state.write_cmd = val;
     ~~~~~~~~~~~~~~~~^~~~~
  hw/i8042.c:298:5: note: ‘value’ was declared here
    u8 value;
       ^~~~~
  cc1: all warnings being treated as errors
  make: *** [Makefile:508: hw/i8042.o] Error 1

Signed-off-by: hbuxiaofei <hbuxiaofei@gmail.com>
Link: https://lore.kernel.org/r/20221102080501.69274-1-hbuxiaofei@gmail.com


Signed-off-by: Will Deacon <will@kernel.org>