gmetad: avoid always false check due to use of unsigned in readline r…

…eturn

len is defined as socklen_t which is an opaque type usually defined to be
unsigned with up to 32bits, check for values lower than 0 will be always
false, so use an int instead.

gmetad/server.c

@@ -541,6 +541,7 @@ server_thread (void *arg)
 {
    int interactive = (arg != NULL);
    socklen_t len;
+   int request_len;
    client_t client;
    char remote_ip[16];
    char request[REQUESTLEN + 1];
@@ -594,8 +595,8 @@ server_thread (void *arg)
 
          if (interactive)
             {
-               len = readline(client.fd, request, REQUESTLEN);
-               if (len<0)
+               request_len = readline(client.fd, request, REQUESTLEN);
+               if (request_len < 0)
                   {
                      err_msg("server_thread() could not read request from %s", remote_ip);
                      close(client.fd);