tidy-up: drop stray "unused" comments

Closes #18453

docs/examples/cacertinmem.c

@@ -72,8 +72,8 @@ static CURLcode sslctx_function(CURL *curl, void *sslctx, void *pointer)
   int i;
   STACK_OF(X509_INFO) *inf;
 
-  (void)curl; /* avoid warnings */
-  (void)pointer; /* avoid warnings */
+  (void)curl;
+  (void)pointer;
 
   if(!cts || !cbio) {
     return rv;

docs/examples/chkspeed.c

@@ -56,8 +56,8 @@ static size_t WriteCallback(void *ptr, size_t size, size_t nmemb, void *data)
 {
   /* we are not interested in the downloaded bytes itself,
      so we only return the size we would have saved ... */
-  (void)ptr;  /* unused */
-  (void)data; /* unused */
+  (void)ptr;
+  (void)data;
   return (size_t)(size * nmemb);
 }
 

docs/examples/debug.c

@@ -90,7 +90,7 @@ int my_trace(CURL *handle, curl_infotype type,
 {
   struct data *config = (struct data *)userp;
   const char *text;
-  (void)handle; /* prevent compiler warning */
+  (void)handle;
 
   switch(type) {
   case CURLINFO_TEXT:

docs/examples/http2-download.c

@@ -110,7 +110,7 @@ int my_trace(CURL *handle, curl_infotype type,
   const char *text;
   struct transfer *t = (struct transfer *)userp;
   unsigned int num = t->num;
-  (void)handle; /* prevent compiler warning */
+  (void)handle;
 
   switch(type) {
   case CURLINFO_TEXT:

docs/examples/http2-pushinmemory.c

@@ -97,8 +97,8 @@ static int server_push_callback(CURL *parent,
 {
   char *headp;
   int *transfers = (int *)userp;
-  (void)parent; /* we have no use for this */
-  (void)num_headers; /* unused */
+  (void)parent;
+  (void)num_headers;
 
   if(pushindex == MAX_FILES)
     /* cannot fit anymore */

docs/examples/http2-serverpush.c

@@ -92,7 +92,7 @@ int my_trace(CURL *handle, curl_infotype type,
              void *userp)
 {
   const char *text;
-  (void)handle; /* prevent compiler warning */
+  (void)handle;
   (void)userp;
   switch(type) {
   case CURLINFO_TEXT:
@@ -171,7 +171,7 @@ static int server_push_callback(CURL *parent,
   FILE *out;
   static unsigned int count = 0;
 
-  (void)parent; /* we have no use for this */
+  (void)parent;
 
   curl_msnprintf(filename, 128, "push%u", count++);
 

docs/examples/http2-upload.c

@@ -150,7 +150,7 @@ int my_trace(CURL *handle, curl_infotype type,
   struct timeval tv;
   time_t secs;
   struct tm *now;
-  (void)handle; /* prevent compiler warning */
+  (void)handle;
 
   gettimeofday(&tv, NULL);
   if(!known_offset) {

docs/examples/multi-debugcallback.c

@@ -91,7 +91,7 @@ int my_trace(CURL *handle, curl_infotype type,
   const char *text;
 
   (void)userp;
-  (void)handle; /* prevent compiler warning */
+  (void)handle;
 
   switch(type) {
   case CURLINFO_TEXT:

docs/examples/threaded-ssl.c

@@ -72,7 +72,7 @@ int main(int argc, char **argv)
 {
   pthread_t tid[NUMT];
   int i;
-  (void)argc; /* we do not use any arguments in this example */
+  (void)argc;
   (void)argv;
 
   /* Must initialize libcurl before any threads are started */

docs/examples/usercertinmem.c

@@ -93,8 +93,8 @@ static CURLcode sslctx_function(CURL *curl, void *sslctx, void *pointer)
     "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX\n"
     "-----END RSA PRIVATE KEY-----\n";
 
-  (void)curl; /* avoid warnings */
-  (void)pointer; /* avoid warnings */
+  (void)curl;
+  (void)pointer;
 
   /* get a BIO */
   bio = BIO_new_mem_buf((char *)mypem, -1);