Fix compiler warning: conditional expression is constant

ares/acountry.c

@@ -199,7 +199,7 @@ int main(int argc, char **argv)
  */
 static void wait_ares(ares_channel channel)
 {
-  while (1)
+  for (;;)
     {
       struct timeval *tvp, tv;
       fd_set read_fds, write_fds;

ares/adig.c

@@ -321,7 +321,7 @@ int main(int argc, char **argv)
     }
 
   /* Wait for all queries to complete. */
-  while (1)
+  for (;;)
     {
       FD_ZERO(&read_fds);
       FD_ZERO(&write_fds);

ares/ahost.c

@@ -140,7 +140,7 @@ int main(int argc, char **argv)
     }
 
   /* Wait for all queries to complete. */
-  while (1)
+  for (;;)
     {
       FD_ZERO(&read_fds);
       FD_ZERO(&write_fds);

ares/ares__read_line.c

@@ -44,7 +44,7 @@ int ares__read_line(FILE *fp, char **buf, size_t *bufsize)
       *bufsize = 128;
     }
 
-  while (1)
+  for (;;)
     {
       if (!fgets(*buf + offset, (int)(*bufsize - offset), fp))
         return (offset != 0) ? 0 : (ferror(fp)) ? ARES_EFILE : ARES_EOF;