stats: create /run/vpp before stat socket bind()

When VPP tries to bind to stats.sock it will complain about non-existing
/run/vpp directory.
/run/vpp is created before cli socket operations are performed.
The same should be done for stat socket.

Ticket: VPP-1708
Type: fix
Change-Id: I53d70939c8125d04a365ac51a6cbf8926dc52adf
Signed-off-by: YohanPipereau <ypiperea@cisco.com>
Signed-off-by: Ole Troan <ot@cisco.com>
diff --git a/src/vpp-api/python/vpp_papi/vpp_stats.py b/src/vpp-api/python/vpp_papi/vpp_stats.py
index eeaa32d..aa57613 100644
--- a/src/vpp-api/python/vpp_papi/vpp_stats.py
+++ b/src/vpp-api/python/vpp_papi/vpp_stats.py
@@ -192,7 +192,7 @@
 class VPPStats(object):
     VPPStatsIOError = VPPStatsIOError
 
-    default_socketname = '/var/run/vpp/stats.sock'
+    default_socketname = '/run/vpp/stats.sock'
     sharedlib_name = 'libvppapiclient.so'
 
     def __init__(self, socketname=default_socketname, timeout=10):