usb: dwc3: gadget: Do not restart usb upon end transfer cmd timeout

During chapter9 USB3 CV testcase, End transfer command timeout
happening upon set_config 0. Because of the incorrect logic in driver
restarting usb session for this command timeout and causing failures
in CV test. Hence change the logic to do not restart usb session for
end transfer command timeout.

Change-Id: I03baf50456c45e5531e5138976f86cb4bd5e3b0b
Signed-off-by: Chandana Kishori Chiluveru <cchiluve@codeaurora.org>