I suggest to make the vdso_install step independent as
in following patch.

This solves the issue at ahnd and still gives us the posibility
to install the files should they be needed.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>