[master] 2ebf30f Make MAKEFLAGS override-able

[Dridi Boukelmoune]

commit 2ebf30f4030c3e77c4838080f5184bb9cb137308
Author: Dridi Boukelmoune <dridi.boukelmoune at gmail.com>
Date:   Fri Nov 18 15:56:29 2016 +0100

    Make MAKEFLAGS override-able

diff --git a/tools/vtest.sh b/tools/vtest.sh
index cb1b5b2..33152e4 100644
--- a/tools/vtest.sh
+++ b/tools/vtest.sh
@@ -31,7 +31,7 @@ set -e
 #######################################################################
 # Parameters
 
-export MAKEFLAGS=-j2
+export MAKEFLAGS="${MAKEFLAGS:--j2}"
 
 export TMPDIR=`pwd`/tmp
 mkdir -p tmp