usb: change to one-pass probing of device drivers

This brings USB bus more in line with how newbus is supposed to be used.
Also, because of the two-pass probing the following message was produced
by devd in default configuration when almost any USB device was
connected:
	Unknown USB device: vendor <> product <> bus <>
This should be fixed now.

Note that many USB device drivers pass some information from probe
method to attach method via ivars.  For this to continue working we rely
on the fact that the subr_bus code calls probe method of a winning driver
again before calling its attach method in the case where multiple
drivers claim to support a device.  This is done because device
description is set in successful probe methods and we want to get a correct
device description from a winning driver.  So now this logic is re-used
for setting ivars too.

Reviewed by:	hselasky
MFC after:	1 month

0 files changed, 0 insertions, 0 deletions