staging: rtl8188eu: remove empty label from mlmeext_joinbss_event_callback

staging: rtl8188eu: remove empty label from mlmeext_joinbss_event_callback

Remove empty label at end of mlmeext_joinbss_event_callback function, as
it only contained a return in my last patch to make the code build. It
is better removed, and the corresponding goto converted to a return.

Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
Link: https://lore.kernel.org/r/20210615223607.13863-2-phil@philpotter.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>