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

lib/vtls/x509asn1.c

@@ -556,7 +556,7 @@ static CURLcode GTime2str(struct dynbuf *store,
                         "%.4s-%.2s-%.2s %.2s:%.2s:%c%c%s%.*s%s%.*s",
                         beg, beg + 4, beg + 6,
                         beg + 8, beg + 10, sec1, sec2,
-                        fracl ? ".": "", (int)fracl, fracp,
+                        fracl ? "." : "", (int)fracl, fracp,
                         sep, (int)tzl, tzp);
 }