tidy-up: miscellaneous

- curl_ntlm_core, smtp, schannel: fix comments.
- curl_setup.h: fix to undef before define.
- tool_doswin, server/sockfilt: reduce variables scopes.
- tool_doswin: drop an interim variable.
- windows: replace `SOCKET_ERROR` with `0` to align with rest of code.
- libssh2: rename variable to align with rest of code.
- gtls, unit1398: use `#if 0`.
- curl_trc.h, curlx/inet_ntop.h: add missing parentheses in macro
  expressions.
- ldap.c: set empty macro to `do {} while(0)`.
- examples/crawler: rename a non-CURLcode `result` variable.
- CURLINFO_TLS_SESSION: drop stray colon.
- add `const` to casts where missing.
- drop unnecessary parentheses.
- fix indent.
- quote style.
- comment style.
- whitespace, newlines, fold/unfold.

Closes #20554

scripts/ciconfig.pl

@@ -170,14 +170,14 @@ scanjobs();
 print "Used configure options (with / without)\n";
 for my $w (sort keys %used) {
     printf "  %s: %d %d%s\n", $w, $with{$w}, $without{$w},
-        $defaulton{$w} ? " (auto)":"";
+        $defaulton{$w} ? " (auto)" : "";
 }
 
 print "Never used configure options\n";
 for my $w (sort keys %avail) {
     if(!$used{$w}) {
         printf "  %s%s\n", $w,
-            $defaulton{$w} ? " (auto)":"";
+            $defaulton{$w} ? " (auto)" : "";
     }
 }