Make automake silent rules default

Change-Id: Ia504ccdac1deac20f20cf7fb76f78b2d8c505474
Signed-off-by: Damjan Marion <damarion@cisco.com>
diff --git a/vnet/configure.ac b/vnet/configure.ac
index bc1922b..8f8b91f 100644
--- a/vnet/configure.ac
+++ b/vnet/configure.ac
@@ -3,7 +3,7 @@
 AC_CONFIG_HEADERS(config/config.h)
 LT_INIT
 AM_INIT_AUTOMAKE
-AM_SILENT_RULES
+AM_SILENT_RULES([yes])
 
 AC_PROG_CC
 AM_PROG_CC_C_O