traps: x86_64: remove trace_hardirqs_fixup from debug handler

All exceptions are taken via interrupt gates. TRACE_IRQS_OFF
is called just before entering the C code, so the irq state
is known to the irq tracer at this point. No need to call
trace_hardirqs_fixup.

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>