Auto merge of rust-lang#15725 - DaniPopes:fix-lintgen, r=Veykril

internal: fix automatic rustc/rustdoc lint generation

Missed in rust-lang#15680: the output of `-Whelp` changed since the last run so it generated some bad rustdoc lints entries.
Also preemptively fix a `-Whelp` breakage that might get merged in rust-lang#116412

Author: bors