Add sw_if_index to af_packet_create and various clean ups

Change-Id: I4c2972b55d5d99f3aa7a05885791eef47351c734
Signed-off-by: Keith Burns (alagalah) <alagalah@gmail.com>
diff --git a/vpp-api-test/vat/vat.h b/vpp-api-test/vat/vat.h
index b32d9ff..4772f2e 100644
--- a/vpp-api-test/vat/vat.h
+++ b/vpp-api-test/vat/vat.h
@@ -125,6 +125,7 @@
     u32 async_errors;
     volatile u32 result_ready;
     volatile i32 retval;
+    volatile u32 sw_if_index;
     volatile u8 *shmem_result;
 
     /* our client index */