Wrong DOM values for xe-* interfaces

[fstolba]

Running latest master targetting multiple platforms (QFX, EX, MX) on multiple Junos versions.

DOM data from xe-* interfaces is wrong (e.g. junos_interface_diagnostics_laser_rx_dbm shows -inf even though the transceiver is inserted and signal is received, verifiable using show int diagnostics optics). 1G optics act the same.

et-* interfaces look fine, no difference 40/100G or 4 lane/2 lane optics for example.

These lines from the log might be relevant:

junos_exporter[85716]: time="2022-03-24T23:54:25Z" level=error msg="Power: expected element type <rpc-reply> but have <command>" source="junos_collector.go:129"