do_build.sh: for PXE builds, symlink latest output

Create a symlink (build-output/_do_build_latest) to the most recent
build output directory. This can be used to specify the location of
an HTTP package repository for PXE installs.

OXT-1736

Signed-off-by: Rich Persaud <rich.persaud@baesystems.com>

Author: Rich Persaud

do_build.sh

@@ -1241,6 +1241,12 @@ do_ship()
 	    do_info
 	    do_logs
 	fi
+
+	pushd $OUTPUT_DIR
+	SYMLINK_OUTPUT="_do_build_latest"
+	rm -f $SYMLINK_OUTPUT
+	ln -s $NAME $SYMLINK_OUTPUT
+	popd
 }
 
 do_copy()