usb: dwc3: gadget: combine return points into a single one

usb: dwc3: gadget: combine return points into a single one

Upstream Linux commit c0ca324d09a0.

dwc3_send_gadget_ep_cmd() had three return
points. That becomes a pain to track when we need to
debug something or if we need to add more code
before returning.

Let's combine all three return points into a single
one just by introducing a local 'ret' variable.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Link: https://lore.kernel.org/r/20240412202611.3565052-2-alexander.sverdlin@siemens.com
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>