usb: gadget: xudc: not unhalt ep in unhalted

usb: gadget: xudc: not unhalt ep in unhalted

Unhalt ep is not necessary if ep is already in unhalted state. And, it
will cause racing between ep reload in device side and ep transfer
request from host side and results in the ep stuck in flow control
state. Removed unhalt ep in unhalted state here to avoid the racing.

Bug 200420663

Change-Id: I0dabe91aa5b864b7f1bb73d7c8bb2ea1150efd5f
Signed-off-by: Henry Lin <henryl@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1781018
(cherry picked from commit bfb2eab210d8477af49a542621f343055dd696a0)
Reviewed-on: https://git-master.nvidia.com/r/1801778
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>