net/eth.c: eth_mac_skip() is only needed when CONFIG_NET_MULTI is set

Move it inside the #ifdef CONFIG_NET_MULTI to avoid

	eth.c:64: warning: 'eth_mac_skip' defined but not used

messages from a number of old, non-CONFIG_NET_MULTI boards.

Signed-off-by: Wolfgang Denk <wd@denx.de>
Signed-off-by: Ben Warren <biggerbadderben@gmail.com>

net/eth.c

@@ -60,6 +60,8 @@ int eth_getenv_enetaddr_by_index(int index, uchar *enetaddr)
 	return eth_getenv_enetaddr(enetvar, enetaddr);
 }
 
+#ifdef CONFIG_NET_MULTI
+
 static int eth_mac_skip(int index)
 {
 	char enetvar[15];
@@ -68,8 +70,6 @@ static int eth_mac_skip(int index)
 	return ((skip_state = getenv(enetvar)) != NULL);
 }
 
-#ifdef CONFIG_NET_MULTI
-
 /*
  * CPU and board-specific Ethernet initializations.  Aliased function
  * signals caller to move on