usb-storage: Drop useless null test in usb_msd_handle_data() scsi_req_new() never returns null, and scsi_req_enqueue() dereferences the pointer, so checking for null is useless. Spotted by Coverity. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>