tulip: Assign default MAC address if not specified

tulip: Assign default MAC address if not specified

The MAC of the tulip card is stored in the EEPROM and at startup
tulip_fill_eeprom() is called to initialize the EEPROM with the MAC
address given on the command line, e.g.:
    -device tulip,mac=00:11:22:33:44:55

In case the mac address was not given on the command line,
tulip_fill_eeprom() initializes the MAC in EEPROM with 00:00:00:00:00:00
which breaks e.g. a HP-UX guest.

Fix this problem by moving qemu_macaddr_default_if_unset() a few lines
up, so that a default mac address is assigned before tulip_fill_eeprom()
initializes the EEPROM.

Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>