compulab: eeprom: propagate error value in read_mac_addr()

cl_eeprom_read_mac_addr() doesn't differentiate between success case and
inability to access eeprom. Fix this by propagating the return value of
cl_eeprom_setup().

Cc: Stefano Babic <sbabic@denx.de>
Cc: Igor Grinberg <grinberg@compulab.co.il>
Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>
Acked-by: Igor Grinberg <grinberg@compulab.co.il>

board/compulab/common/eeprom.c

@@ -105,9 +105,11 @@ void get_board_serial(struct tag_serialnr *serialnr)
 int cl_eeprom_read_mac_addr(uchar *buf, uint eeprom_bus)
 {
 	uint offset;
+	int err;
 
-	if (cl_eeprom_setup(eeprom_bus))
-		return 0;
+	err = cl_eeprom_setup(eeprom_bus);
+	if (err)
+		return err;
 
 	offset = (cl_eeprom_layout != LAYOUT_LEGACY) ?
 			MAC_ADDR_OFFSET : MAC_ADDR_OFFSET_LEGACY;