KVM: selftests: Remove unused macro in the hardware disable test

The macro GUEST_CODE_PIO_PORT is never referenced in the code,
just remove it.

Signed-off-by: Ba Jing <bajing@cmss.chinamobile.com>
Link: https://lore.kernel.org/r/20240903043135.11087-1-bajing@cmss.chinamobile.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: Ba Jing

tools/testing/selftests/kvm/hardware_disable_test.c

@@ -20,7 +20,6 @@
 #define SLEEPING_THREAD_NUM (1 << 4)
 #define FORK_NUM (1ULL << 9)
 #define DELAY_US_MAX 2000
-#define GUEST_CODE_PIO_PORT 4
 
 sem_t *sem;