ISAPNP: removed unused isapnp_detected and ISAPNP_DEBUG

ISAPNP_DEBUG isn't used at all.  isapnp_detected is set but never read.
So remove them both.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Acked-by: Adam Belay <abelay@novell.com>
Signed-off-by: Len Brown <len.brown@intel.com>