CVE-2026-64569 mpls: fix NULL deref in mpls_valid_fib_dump_req() on CONFIG_INET=n

In the Linux kernel, the following vulnerability has been resolved: mpls: fix NULL deref in mplsvalidfibdumpreq on CONFIGINET=n On CONFIGINET=n builds, mplsvalidfibdumpreq walks the parsed attribute table itself instead of calling ipvalidfibdumpreq. The RTAOIF arm passes tbRTAOIF to nlagetu32...