usb: dwc3: gadget: don't wrap around the TRB poll on non-ISOC

usb: dwc3: gadget: don't wrap around the TRB poll on non-ISOC

commit 8d62cd65d74d0e241b3a152f7347bb66126b705b upstream.

If we have a non-ISOC endpoint, we will not have a Link TRB
pointing to the beginning of the TRB pool. On such endpoints,
we don't want to let the driver wrap around the TRB pool
otherwise controller will hang waiting for a valid TRB.

Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>