hw/input/pxa2xx_keypad: Replace hw_error() by qemu_log_mask()

hw/input/pxa2xx_keypad: Replace hw_error() by qemu_log_mask()

hw_error() calls exit(). This a bit overkill when we can log
the accesses as unimplemented or guest error.

When fuzzing the devices, we don't want the whole process to
exit. Replace some hw_error() calls by qemu_log_mask()
(missed in commit 5a0001ec7e).

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20200525114123.21317-2-f4bug@amsat.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>