Impact: cleanup

DISABLE_INTERRUPTS(CLBR_NONE)/TRACE_IRQS_OFF is now always
executed just before paranoid_exit. Move it there.

Split out paranoidzeroentry, paranoiderrorentry, and
paranoidzeroentry_ist to get more readable macro's.
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>