session: add support for memfd segments

- update segment manager and session api to work with both flavors of
  ssvm segments
- added generic ssvm slave/master init and del functions
- cleanup/refactor tcp_echo
- fixed uses of svm fifo pool as vector

Change-Id: Ieee8b163faa407da6e77e657a2322de213a9d2a0
Signed-off-by: Florin Coras <fcoras@cisco.com>
diff --git a/src/vppinfra/linux/mem.c b/src/vppinfra/linux/mem.c
index 3c44922..350ccf8 100644
--- a/src/vppinfra/linux/mem.c
+++ b/src/vppinfra/linux/mem.c
@@ -61,7 +61,7 @@
   return min_log2 (clib_mem_vm_get_page_size (fd));
 }
 
-static void
+void
 clib_mem_vm_randomize_va (uword * requested_va, u32 log2_page_size)
 {
   u8 bit_mask = 15;