isisd: fix rcap tlv double-free crash

[louis-6wind]

Fix rcap tlv double-free crash. It is supposed to freed later by isis_free_tlvs() -> free_tlv_router_cap().

Fixes: 49efc80d34 ("isisd: Ensure rcap is freed in error case")

[louis-6wind]

ci:rerun

[ton31337]

@Mergifyio backport stable/10.1 stable/10.0 stable/9.1 stable/9.0

[mergify[bot]]

backport stable/10.1 stable/10.0 stable/9.1 stable/9.0

✅ Backports have been created

• #16842 isisd: fix rcap tlv double-free crash (backport #16809) has been created for branch stable/10.1
• #16843 isisd: fix rcap tlv double-free crash (backport #16809) has been created for branch stable/10.0
• #16844 isisd: fix rcap tlv double-free crash (backport #16809) has been created for branch stable/9.1
• #16845 isisd: fix rcap tlv double-free crash (backport #16809) has been created for branch stable/9.0 but encountered conflicts

[donaldsharp]

LGTM

[louis-6wind]

LGTM

please also approve to remove the merging blocker