mx53ard: Initialize return code with error

The variable "rc" is the return of board_eth_init() function. Initialize
it with an error code, so that this function can return an error when
CONFIG_SMC911X is not set.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Stefano Babic <sbabic@denx.de>

board/freescale/mx53ard/mx53ard.c

@@ -287,7 +287,7 @@ int board_init(void)
 
 int board_eth_init(bd_t *bis)
 {
-	int rc = 0;
+	int rc = -ENODEV;
 
 	weim_smc911x_iomux();
 	weim_cs1_settings();