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/bgpd/bgp_fsm.c b/bgpd/bgp_fsm.c
index d261bb5..6a2e41e 100644
--- a/bgpd/bgp_fsm.c
+++ b/bgpd/bgp_fsm.c
@@ -65,7 +65,7 @@
 static int
 bgp_start_jitter (int time)
 {
-  return ((rand () % (time + 1)) - (time / 2));
+  return ((random () % (time + 1)) - (time / 2));
 }
 
 /* Check if suppress start/restart of sessions to peer. */