driver core: check start node in klist_iter_init_node

driver core: check start node in klist_iter_init_node

klist_iter_init_node() takes a node as a start argument.
However, this node might not be valid anymore.
This patch updates the klist_iter_init_node() and
dependent functions to return an error if so.
All calling functions have been audited to check
for a return code here.

Signed-off-by: Hannes Reinecke <[email protected]>
Cc: Greg Kroah-Hartmann <[email protected]>
Cc: Kay Sievers <[email protected]>
Cc: Stable Kernel <[email protected]>
Cc: Linux Kernel <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>