[media] em28xx: rename function em28xx_uninit_isoc to em28xx_uninit_usb_xfer

This function will be used to uninitialize USB bulk transfers, too.
Also rename the local variable isoc_bufs to usb_bufs.

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