staging: rtl8723bs: core: Remove return variables in rtw_mlme_ext.c

Remove unnecessary local return variables in rtw_mlme_ext.c. Issue found
with Coccinelle using ret.cocci.

Signed-off-by: Nishka Dasgupta <nishka.dasgupta@yahoo.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>