Make sure it creates the directory where tarballs are stored if it doesn't exist.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@40035 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

distrib/scripts/pre-flight.sh

@@ -38,8 +38,8 @@ else
 fi
 
 # this is where we will store the wxAll tarball we create
-if [ ! -d $DISTDIR ]; then
-  mkdir $DISTDIR
+if [ ! -d $START_DIR/$DISTDIR ]; then
+  mkdir -p $START_DIR/$DISTDIR
 fi
 
 #re-bake the bakefiles