[SfpUtil] sfp eeprom with option dom is not working on Xcvrs with flat memory

[vivekrnv]

Description

Steps to reproduce the issue:

root@switch/home/admin# sfputil show eeprom -d -p Ethernet0
Traceback (most recent call last):
  File "/usr/local/bin/sfputil", line 8, in <module>
    sys.exit(cli())
             ^^^^^
  File "/usr/local/lib/python3.11/dist-packages/click/core.py", line 764, in __call__
    return self.main(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/dist-packages/click/core.py", line 717, in main
    rv = self.invoke(ctx)
         ^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/dist-packages/click/core.py", line 1137, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/dist-packages/click/core.py", line 1137, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/dist-packages/click/core.py", line 956, in invoke
    return ctx.invoke(self.callback, **ctx.params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/dist-packages/click/core.py", line 555, in invoke
    return callback(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/dist-packages/sfputil/main.py", line 677, in eeprom
    xcvr_dom_info = platform_chassis.get_sfp(physical_port).get_transceiver_bulk_status()
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/dist-packages/sonic_platform_base/sonic_xcvr/sfp_optoe_base.py", line 32, in get_transceiver_bulk_status
    return api.get_transceiver_bulk_status() if api is not None else None
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/dist-packages/sonic_platform_base/sonic_xcvr/api/public/cmis.py", line 233, in get_transceiver_bulk_status
    self.vdm_dict = self.get_vdm(self.vdm.VDM_REAL_VALUE)
                                 ^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'VDM_REAL_VALUE'

get_transceiver_bulk_status call is failing

Describe the results you received:

Related to sonic-net/sonic-platform-common#397

Fixed a similar issue in xcvrd here: sonic-net/sonic-platform-daemons#458

But sfputil lacks any safeguards.

Also, no "TRANSCEIVER_DOM_INFO" table entries are seen on these sfp's

Describe the results you expected:

No Exception must be throws

Output of show version:

Latest master

[vivekrnv]

@chiourung FYI

[gechiang]

@prgeor is this something expected? Flat memory is not supported? Can you help check with the original PR submitter @chiourung to see if this is something require changes in sfputil as well? Any other places may also need this?

[prgeor]

@mihirpat1 can you address this

[vivekrnv]

Note: Only seen on master, not on 202311