Some mt7603e chip has empty efuse data.
In this case driver will crash due to dereferencing NULL pointer.
The mt7603_eeprom_load will return success directly if the chip has no efuse
data and dev->mt76.otp.data is left empty, i.e. NULL pointer.
The mt7603_eeprom_init will then try to dereference dev->mt76.otp.data
without checking its value.
This patch adds a check around these codes to prevent kernel panic.
Signed-off-by: Weijie Gao <[email protected]>
