lib: fix conversion warnings with gcc on macOS

docs/examples/multi-legacy.c

@@ -102,7 +102,7 @@ int main(void)
       if(timeout.tv_sec > 1)
         timeout.tv_sec = 1;
       else
-        timeout.tv_usec = (curl_timeo % 1000) * 1000;
+        timeout.tv_usec = (int)(curl_timeo % 1000) * 1000;
     }
 
     /* get file descriptors from the transfers */

docs/examples/sendrecv.c

@@ -38,7 +38,7 @@ static int wait_on_socket(curl_socket_t sockfd, int for_recv, long timeout_ms)
   int res;
 
   tv.tv_sec = timeout_ms / 1000;
-  tv.tv_usec = (timeout_ms % 1000) * 1000;
+  tv.tv_usec = (int)(timeout_ms % 1000) * 1000;
 
   FD_ZERO(&infd);
   FD_ZERO(&outfd);

src/tool_cb_rea.c

@@ -65,7 +65,7 @@ size_t tool_read_cb(char *buffer, size_t sz, size_t nmemb, void *userdata)
 
       /* wait this long at the most */
       timeout.tv_sec = wait/1000;
-      timeout.tv_usec = (wait%1000)*1000;
+      timeout.tv_usec = (int)((wait%1000)*1000);
 
       FD_ZERO(&bits);
       FD_SET(in->fd, &bits);

tests/libtest/lib530.c

@@ -162,7 +162,7 @@ static int curlTimerCallback(CURLM *multi, long timeout_ms, void *userp)
   }
   if(timeout_ms != -1) {
     *timeout = tutil_tvnow();
-    timeout->tv_usec += timeout_ms * 1000;
+    timeout->tv_usec += (int)timeout_ms * 1000;
   }
   else {
     timeout->tv_sec = -1;

tests/libtest/lib582.c

@@ -136,7 +136,7 @@ static int curlTimerCallback(CURLM *multi, long timeout_ms, void *userp)
   (void)multi; /* unused */
   if(timeout_ms != -1) {
     *timeout = tutil_tvnow();
-    timeout->tv_usec += timeout_ms * 1000;
+    timeout->tv_usec += (int)timeout_ms * 1000;
   }
   else {
     timeout->tv_sec = -1;