examples: fix more empty expression statement has no effect

Follow-up to 26e46617b9

docs/examples/http2-pushinmemory.c

@@ -163,7 +163,7 @@ int main(void)
      * easy handles but *we* need to clean them up when they are done.
      */
     do {
-      int msgq = 0;;
+      int msgq = 0;
       m = curl_multi_info_read(multi, &msgq);
       if(m && (m->msg == CURLMSG_DONE)) {
         CURL *e = m->easy_handle;

docs/examples/http2-serverpush.c

@@ -315,7 +315,7 @@ int main(void)
      */
 
     do {
-      int msgq = 0;;
+      int msgq = 0;
       m = curl_multi_info_read(multi_handle, &msgq);
       if(m && (m->msg == CURLMSG_DONE)) {
         CURL *e = m->easy_handle;

docs/examples/rtsp.c

@@ -62,16 +62,19 @@ static int _getch(void)
 
 /* error handling macros */
 #define my_curl_easy_setopt(A, B, C)                               \
+  do {                                                             \
     res = curl_easy_setopt((A), (B), (C));                         \
     if(res != CURLE_OK)                                            \
       fprintf(stderr, "curl_easy_setopt(%s, %s, %s) failed: %d\n", \
-            #A, #B, #C, res);
+              #A, #B, #C, res);                                    \
+  } while(0)
 
 #define my_curl_easy_perform(A)                                         \
+  do {                                                                  \
     res = curl_easy_perform(A);                                         \
     if(res != CURLE_OK)                                                 \
-    fprintf(stderr, "curl_easy_perform(%s) failed: %d\n", #A, res);
-
+      fprintf(stderr, "curl_easy_perform(%s) failed: %d\n", #A, res);   \
+  } while(0)
 
 /* send RTSP OPTIONS request */
 static void rtsp_options(CURL *curl, const char *uri)