scripts: improve the decodecode script

kerneloops.org has been using an improved "decodecode" script,
specifically it has a special marker that shows which line in the assembly
the oops happened at, like this:

  20:	83 e0 03             	and    $0x3,%eax
  23:	09 d8                	or     %ebx,%eax
  25:	85 db                	test   %ebx,%ebx
  27:	89 02                	mov    %eax,(%edx)
  29:	74 0f                	je     0x3a
  2b:*	3b 73 04             	cmp    0x4(%ebx),%esi     <-- trapping instruction
  2e:	75 05                	jne    0x35
  30:	89 53 04             	mov    %edx,0x4(%ebx)
  33:	eb 07                	jmp    0x3c
  35:	89 53 08             	mov    %edx,0x8(%ebx)

this patch updates the kernel copy to also have this functionality.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Reviewed-by: WANG Cong <wangcong@zeuux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>