staging: rtl8188eu: convert unsigned char array to u8

Convert array bcast_addr from unsigned char to u8.
Clears a line over 80 characters checkpatch warning.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20191026121135.181897-2-straube.linux@gmail.com


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