staging: r8712u: use is_zero_ether_addr() instead of memcmp()

Using is_zero_ether_addr() instead of directly use
memcmp(addr, "\x00\x00\x00\x00\x00\x00", ETH_ALEN)
to determine if the ethernet address is all zeros.

spatch with a semantic match is used to found this problem.
(http://coccinelle.lip6.fr/)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8712/rtl871x_recv.c

@@ -32,6 +32,7 @@
 #include <linux/slab.h>
 #include <linux/if_ether.h>
 #include <linux/kmemleak.h>
+#include <linux/etherdevice.h>
 
 #include "osdep_service.h"
 #include "drv_types.h"
@@ -331,8 +332,8 @@ static sint sta2sta_data_frame(struct _adapter *adapter,
 			return _FAIL;
 		if ((memcmp(myhwaddr, pattrib->dst, ETH_ALEN)) && (!bmcast))
 			return _FAIL;
-		if (!memcmp(pattrib->bssid, "\x0\x0\x0\x0\x0\x0", ETH_ALEN) ||
-		    !memcmp(mybssid, "\x0\x0\x0\x0\x0\x0", ETH_ALEN) ||
+		if (is_zero_ether_addr(pattrib->bssid) ||
+		    is_zero_ether_addr(mybssid) ||
 		    (memcmp(pattrib->bssid, mybssid, ETH_ALEN)))
 			return _FAIL;
 		sta_addr = pattrib->src;
@@ -409,8 +410,8 @@ static sint ap2sta_data_frame(struct _adapter *adapter,
 		if ((memcmp(myhwaddr, pattrib->dst, ETH_ALEN)) && (!bmcast))
 			return _FAIL;
 		/* check BSSID */
-		if (!memcmp(pattrib->bssid, "\x0\x0\x0\x0\x0\x0", ETH_ALEN) ||
-		     !memcmp(mybssid, "\x0\x0\x0\x0\x0\x0", ETH_ALEN) ||
+		if (is_zero_ether_addr(pattrib->bssid) ||
+		     is_zero_ether_addr(mybssid) ||
 		     (memcmp(pattrib->bssid, mybssid, ETH_ALEN)))
 			return _FAIL;
 		if (bmcast)