remove some #ifdef DEBUG_UNUSED_IOPORT in ioport.c
and use PRIx32 where appropriate

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Cc: Anthony Liguori <anthony@codemonkey.ws>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>