I'm applying Dan's patches by hand to double check everything and I
wanted to get a couple of the trivial ones out of the way first.

This patch fixes a bug where errors on the submit path wouldn't remove
URB's from the HC linked list.

  If we fail adding the URB to the schedule, we need to make
  sure that we remove it from the urb_list. Thanks to
  Dan Streetman for finding and fixing this bug.