What were you trying to do that didn't work?

This is cloned from https://issues.redhat.com/browse/RHEL-30960

Under following configuration, the SMA1 input signal is valid and DPLLs are locked on SMA1 currently.
But synce4l select the "NON_EXIST" external source as best source wrongly.
There is no DPLL pin using label "NON_EXIST".

```
[global]
logging_level 7
use_syslog 0
verbose 1
message_tag [synce4l]

[<synce1>]
network_option 2
extended_tlv 0
recover_time 60
clock_id 5799633565436792966
module_name ice

[ens1f0]
tx_heartbeat_msec 1000
rx_heartbeat_msec 500
allowed_qls 0x4
allowed_ext_qls 0xFF,0x20

[

]
board_label non-exist
input_QL 0x1
input_ext_QL 0x20

[\{SMA1}]
board_label SMA1
input_QL 0xA
input_ext_QL 0xFF
```

Please provide the package NVR for which bug is seen:

[root@dell-per740-83 topo]# rpm -q synce4l

synce4l-1.0.0-2.el10.x86_64

[root@dell-per740-83 topo]# uname -r

6.9.0-6.el10.x86_64

How reproducible:

always

Steps to reproduce

1. enable SMA1 input on local system and enable SMA1 output on remote system
2. start synce4l using follow cfg file: synce4l -f synce.cfg
[root@dell-per740-83 topo]# cat synce.cfg
[global]
logging_level 7
use_syslog 0
verbose 1
message_tag [synce4l]

[<synce1>]
network_option 2
extended_tlv 0
recover_time 60
clock_id 5799633565436792966
module_name ice

[ens1f0]
tx_heartbeat_msec 1000
rx_heartbeat_msec 500
allowed_qls 0x4
allowed_ext_qls 0xFF,0x20

[{NON_EXIST}

]
board_label non-exist
input_QL 0x1
input_ext_QL 0x20

[

]
board_label SMA1
input_QL 0xA
input_ext_QL 0xFF
3. monitor log, found synce4l selected NON_EXIST as source
synce4l[5034.982]: [synce4l] EEC_LOCKED/EEC_LOCKED_HO_ACQ on NON_EXIST of synce1
synce4l[5034.982]: [synce4l] act on EEC_LOCKED/EEC_LOCKED_HO_ACQ for ens1f0
synce4l[5035.709]: [synce4l] tx_rebuild_tlv: attached new TLV, QL=0x1 on ens1f0
synce4l[5037.367]: [synce4l] dpll_id:0 received on synce1
synce4l[5037.367]: [synce4l] mode:2 received on synce1
synce4l[5037.367]: [synce4l] lock status:3 received on synce1
^Csynce4l[5046.085]: [synce4l] synce_clock_destroy
synce4l[5046.085]: [synce4l] dpll mon for synce1 new state: 11
synce4l[5046.094]: [synce4l] dpll_mon thread exit state 12=OK for synce1
synce4l[5046.135]: [synce4l] synce_port_ctrl_destroy on ens1f0
synce4l[5046.710]: [synce4l] tx thread exit state 3=OK port ens1f0
synce4l[5047.232]: [synce4l] rx thread exit state 3=OK port ens1f0

Expected results

select SMA1 as source

Actual results

selected NON_EXIST as source