bna: Convert MAC_ADDRLEN uses to ETH_ALEN

Reduce the number of #defines, use the normal #define from if_ether.h
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/brocade/bna/cna.h

@@ -43,8 +43,7 @@ extern char bfa_version[];
 
 #pragma pack(1)
 
-#define MAC_ADDRLEN	(6)
-typedef struct mac { u8 mac[MAC_ADDRLEN]; } mac_t;
+typedef struct mac { u8 mac[ETH_ALEN]; } mac_t;
 
 #pragma pack()