Driver core: accept all valid action-strings in uevent-trigger

This allows the uevent file to handle any type of uevent action to be
triggered by userspace instead of just the "add" uevent.


Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>