mac80211: rt2x00: fix eeprom load from PCI eFuse
When eeprom name is not defined, the file load function should
return an error code so that it can fallthrough to read eeprom
form NIC inside eFuse.
Fixes: https://github.com/openwrt/openwrt/issues/17854
Signed-off-by: Shiji Yang <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/17892
Signed-off-by: Hauke Mehrtens <[email protected]>