[media] em28xx: remove double checks for urb->status == -ENOENT in urb_data_copy functions

This check is already done in the URB handler
em28xx_irq_callback before calling these functions.

Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>