Driver core: add new device to bus's list before probing

Driver core: add new device to bus's list before probing

This patch (as1271) affects when new devices get linked into their
bus's list of devices.  Currently this happens after probing, and it
doesn't happen at all if probing fails.  Clearly this is wrong,
because at that point quite a few symbolic links have already been
created in sysfs.  We are committed to adding the device, so it should
be linked into the bus's list regardless.

In addition, this needs to happen before the uevent announcing the new
device gets issued.  Otherwise user programs might try to access the
device before it has been added to the bus.

To fix both these problems, the patch moves the call to
klist_add_tail() forward from bus_attach_device() to bus_add_device().
Since bus_attach_device() now does nothing but probe for drivers, it
has been renamed to bus_probe_device().  And lastly, the kerneldoc is
updated.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>