USB: usblp: Remove checks no longer needed with the new runtime PM system

Under the new system a device cannot be suspended against
the driver's wish. Therefore this condition no longer needs
to be checked for.

Signed-off-by: Oliver Neukum <oliver@neukum.org>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>