Fix following crash in `show version`:
```
Traceback (most recent call last):
File "/usr/local/bin/decode-syseeprom", line 32, in instantiate_eeprom_object
eeprom = sonic_platform.platform.Platform().get_chassis().get_eeprom()
AttributeError: module 'sonic_platform' has no attribute 'platform'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/usr/local/bin/decode-syseeprom", line 262, in <module>
sys.exit(main())
File "/usr/local/bin/decode-syseeprom", line 244, in main
print_serial(use_db)
File "/usr/local/bin/decode-syseeprom", line 169, in print_serial
eeprom = instantiate_eeprom_object()
File "/usr/local/bin/decode-syseeprom", line 34, in instantiate_eeprom_object
log.log_error('Failed to obtain EEPROM object due to {}'.format(repr(e)))
NameError: name 'log' is not defined
```
Signed-off-by: pettershao-ragilenetworks <pettershao@ragilenetworks.com>
