staging: r8188eu: remove unnecessary type casts (struct wlan_bssid_ex *)

Reduce line length, simplify refactoring.

Signed-off-by: Ivan Safonov <insafonov@gmail.com>
Link: https://lore.kernel.org/r/20201004060921.8908-1-insafonov@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>