tidy-up: miscellaneous

- badwords: replace stray synonyms with 'null-terminator'.
- tests/FILEFORMAT.md: tidy up feature descriptions.
- printf: replace stray `%i` masks with `%d` for consistency.
- pytest: add comments for empty excepts to try silencing GitHub CodeQL
  warnings.
- tool1394, unit1675: merge nested `if`s.
- dnscache: fix typo in comment.
- fix whitespace, indent and newlines.

Closes #21921

tests/unit/unit1675.c

@@ -29,7 +29,7 @@ static CURLcode test_unit1675(const char *arg)
 {
   UNITTEST_BEGIN_SIMPLE
 
-    /* Test ipv4_normalize */
+  /* Test ipv4_normalize */
   {
     struct dynbuf host;
     int fails = 0;
@@ -123,13 +123,11 @@ static CURLcode test_unit1675(const char *arg)
           fails++;
         }
       }
-      else {
-        if(rc == HOST_IPV4) {
-          curl_mfprintf(stderr, "ipv4_normalize('%s') succeeded unexpectedly:"
-                        " got '%s'\n",
-                        tests[i].in, curlx_dyn_ptr(&host));
-          fails++;
-        }
+      else if(rc == HOST_IPV4) {
+        curl_mfprintf(stderr, "ipv4_normalize('%s') succeeded unexpectedly:"
+                      " got '%s'\n",
+                      tests[i].in, curlx_dyn_ptr(&host));
+        fails++;
       }
     }
     curlx_dyn_free(&host);
@@ -238,12 +236,10 @@ static CURLcode test_unit1675(const char *arg)
           }
         }
       }
-      else {
-        if(!uc) {
-          curl_mfprintf(stderr, "ipv6_parse('%s') succeeded unexpectedly\n",
-                        tests[i].in);
-          fails++;
-        }
+      else if(!uc) {
+        curl_mfprintf(stderr, "ipv6_parse('%s') succeeded unexpectedly\n",
+                      tests[i].in);
+        fails++;
       }
       curlx_free(u.host);
       curlx_free(u.zoneid);