There will be data toggle error happen for full speed buld-out transfer.
The data toggle bit is saved in qh for non-control transfers, it is wrong
to  check the qtd for that case.

Also fix one static analysis tool issue after fix the data toggle error.

John Youn:
* Added WARN() to warn on improper usage of the
  dwc2_hcd_save_data_toggle() function.
Signed-off-by: NDyson Lee <dyson.lee@intel.com>
Signed-off-by: NTang, Jianqiang <jianqiang.tang@intel.com>
Signed-off-by: NJohn Youn <johnyoun@synopsys.com>
Signed-off-by: NFelipe Balbi <balbi@kernel.org>