x86: don't bother printing compat vdso address

The kernel prints the compat vdso address regardless of whether compat
vdso mode is enabled or not, which is confusing.  Given that this
isn't very interesting information anyway, just remove the printk.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Gerhard Mack <gmack@innerfire.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>