usb: dwc3: gadget: Remove unnecessary checks

Remove 2 unnecessary checks:
1) A request in the started_list must have its trb field set. So
checking for req->trb is unnecessary.

2) An endpoint must have started (and have not ended) for the request to
still be in the started_list. There's no point to check if the endpoint
is started. We had this check because previously the driver didn't
handle the endpoint's started/ended flags for END_TRANSFER command
properly. See commit 9f45581f ("usb: dwc3: gadget: early giveback
if End Transfer already completed").

Change-Id: I5d55f02d25abe06d5601730f1d1d88ee24809d2c
Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Git-commit: 8411993e79df8e54da67613025d620a8a23a24fe
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: Mayank Rana <mrana@codeaurora.org>