staging: rtl8723bs: Replace memset with eth_zero_addr

Use eth_zero_addr to assign zero address to the given address array
instead of memset when the second argument in memset is address
of zero. Coccinelle was used to do the replacement and add the
header file linux/etherdevice.h if not already present.

The Coccinelle semantic patch that makes this change is as follows:
@header@
@@
#include <linux/etherdevice.h>

@r1@
expression e;
@@

-memset(e,0x00,ETH_ALEN);
+eth_zero_addr(e);

@includeheader depends on r1 && !header@
@@
+ #include <linux/etherdevice.h>
#include <...>

Signed-off-by: Arushi Singhal <arushisinghal19971997@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>