Replace HTTP links with HTTPS ones: Documentation/admin-guide

Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For each file:
  If not .svg:
    For each line:
      If doesn't contain `\bxmlns\b`:
        For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
          If both the HTTP and HTTPS versions
          return 200 OK and serve the same content:
            Replace HTTP with HTTPS.

Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Link: https://lore.kernel.org/r/20200627072935.62652-1-grandmaster@al2klimov.de
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/admin-guide/sysctl/fs.rst

@@ -261,7 +261,7 @@ directories like /tmp. The common method of exploitation of this flaw
 is to cross privilege boundaries when following a given symlink (i.e. a
 root process follows a symlink belonging to another user). For a likely
 incomplete list of hundreds of examples across the years, please see:
-http://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=/tmp
+https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=/tmp
 
 When set to "0", symlink following behavior is unrestricted.