staging: vt6656: replaced MAX_PACKET_LEN with ETH_FRAME_LEN

Replaced custom macro with one from include/linux/if_ether.h.
Also removed MAX_LOOKAHEAD_SIZE as it is not used elsewhere.
Signed-off-by: Andres More <more.andres@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/vt6656/mib.c

@@ -363,17 +363,14 @@ void STAvUpdateRDStatCounter(PSStatCounter pStatistic,
     }
     else if ((512 <= cbFrameLength) && (cbFrameLength <= 1023)) {
         pStatistic->dwRsrRxFrmLen512_1023++;
-    }
-    else if ((1024 <= cbFrameLength) && (cbFrameLength <= MAX_PACKET_LEN + 4)) {
+    } else if ((1024 <= cbFrameLength) &&
+	       (cbFrameLength <= ETH_FRAME_LEN + 4)) {
         pStatistic->dwRsrRxFrmLen1024_1518++;
-    } else if (cbFrameLength > MAX_PACKET_LEN + 4) {
+    } else if (cbFrameLength > ETH_FRAME_LEN + 4) {
         pStatistic->dwRsrLong++;
     }
-
 }
 
-
-
 /*
  * Description: Update Rx Statistic Counter and copy Rx buffer
  *

drivers/staging/vt6656/tether.h

@@ -38,16 +38,8 @@
 //
 #define U_ETHER_ADDR_STR_LEN (ETH_ALEN * 2 + 1)
                                         // Ethernet address string length
-
-#define MAX_PACKET_LEN      (ETH_DATA_LEN + ETH_HLEN)
-                                        // 1514
-                                        // max total packet length (tx)
-
-#define MAX_LOOKAHEAD_SIZE  MAX_PACKET_LEN
-
 #define U_MULTI_ADDR_LEN    8           // multicast address length
 
-
 #ifdef __BIG_ENDIAN
 
 #define TYPE_PKT_IP         0x0800      //