osd: Need to setsid() now that global_init_daemonize() not used

Caused by: d55a66c56e

Signed-off-by: David Zafman <dzafman@redhat.com>

src/ceph_osd.cc

@@ -199,6 +199,7 @@ int main(int argc, const char **argv)
       }
       return 0;
     }
+    setsid();
     global_init_postfork_start(g_ceph_context);
   }
   common_init_finish(g_ceph_context);