kernel-doc patches for 4.18

Hi Greg,

Arch Linux recently enabled building the kernel documentation in their PKGBUILD, which turned my normally peaceful build into a spamfest of unescaped braces warnings from Perl.

These are fixed upstream with the following two patches:

701b3a3c0ac4 ("PATCH scripts/kernel-doc") 673bb2dfc364 ("scripts/kernel-doc: Escape all literal braces in regexes")

Could they please be applied to 4.18? They should be clean cherry-picks.

Thanks! Nathan