Quagga: Fix code to use srandom/random

Quagga was using a mix of srand/rand and srandom/random.
Consolidate to use srandom/random which are the POSIX
versions of random number generators

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
diff --git a/ripngd/ripngd.c b/ripngd/ripngd.c
index 4a7f52f..97a1392 100644
--- a/ripngd/ripngd.c
+++ b/ripngd/ripngd.c
@@ -1936,7 +1936,7 @@
 static int
 ripng_update_jitter (int time)
 {
-  return ((rand () % (time + 1)) - (time / 2));
+  return ((random () % (time + 1)) - (time / 2));
 }
 
 void
@@ -3084,7 +3084,7 @@
 ripng_init ()
 {
   /* Randomize. */
-  srand (time (NULL));
+  srandom (time (NULL));
 
   /* Install RIPNG_NODE. */
   install_node (&cmd_ripng_node, ripng_config_write);