[PATCH] pnp bus type fix

This is Adam's pnp probing fix.  It's been reported to fix hangs on several
people's machines.  I don't know if it's official or final, and Adam isn't
contactable at present.  But I'm not aware of the patch causing any
regressions.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>