USB: mos7840: fix port_probe flow

Remove temporary do-while(0) loop used to keep changes minimal.

Fixup indentation, remove some line breaks, and replace break with goto
to maintain flow.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>