[PATCH] perf docs: Fix perf-check manual page built with asciidoctor

[PATCH] perf docs: Fix perf-check manual page built with asciidoctor

Forwarded: https://lore.kernel.org/linux-perf-users/Z-BxCE8WrcRmR_5f@decadent.org.uk/

asciidoctor is more picky than asciidoc about the length of heading
underlines, and currently mis-parses perf-check.txt:

  ASCIIDOC perf-check.1
asciidoctor: ERROR: perf-check.txt: line 1: non-conforming manpage title
asciidoctor: ERROR: perf-check.txt: line 1: name section expected
asciidoctor: WARNING: perf-check.txt: line 2: unterminated example block
asciidoctor: WARNING: perf-check.txt: line 5: unterminated listing block

Fix the length of the title underline so it works properly.

Fixes: 98ad0b77323c ("perf check: Introduce 'check' subcommand")
Signed-off-by: Ben Hutchings <benh@debian.org>
Gbp-Pq: Topic bugfix/all
Gbp-Pq: Name perf-docs-Fix-perf-check-manual-page-built-with-asci.patch