[sfputil] Gracefully handle improper 'specification_compliance' field

[prgeor]

Signed-off-by: Prince George [email protected]

What I did

Gracefully handle improper 'specification_compliance' field

How I did it

The 'specification_compliance' field of transceiver info is expected to be a string representation of a dictionary. However, there is a chance, upon some kind of platform issue that a vendor's platform API returns something like 'N/A'. In this case, sfpshow would crash. Rather than crash, sfpshow should handle this gracefully and output 'N/A' instead.

How to verify it

Run "sfputil show eeprom -d" on a device where the 'specification_compliance' field of transceiver info is not a string representation of a dictionary.

Previous command output (if the output of a command-line utility has changed)

N/A -- sfputil would crash

New command output (if the output of a command-line utility has changed)

Ethernet0: SFP EEPROM detected
Application Advertisement: N/A
Connector: N/A
Encoding: N/A
Extended Identifier: N/A
Extended RateSelect Compliance: N/A
Identifier: N/A
N/A: N/A
Nominal Bit Rate(100Mbs): N/A
Specification compliance:
N/A
Vendor Date Code(YYYY-MM-DD Lot): N/A
Vendor Name: N/A
Vendor OUI: N/A
Vendor PN: N/A
Vendor Rev: N/A
Vendor SN: N/A

[prgeor]

@lguohan can this be merged?