spl: Drop unwanted return in spl_fit_upload_fpga()

This was added by mistake and renders the function useless. Fix it.

Signed-off-by: Simon Glass <sjg@chromium.org>
Fixes: 33c60a38 ("trace: Use notrace for short")
Reported-by: Stefan Herbrechtsmeier <stefan.herbrechtsmeier-oss@weidmueller.com>
Reviewed-by: Oleksandr Suvorov <oleksandr.suvorov@foundries.io>