x86, vdso: Drop now wrong comment

Now that 1b3f2a72 is in, it is very
important that the below lying comment be removed! :-)

Signed-off-by: Borislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/r/20110718191054.GA18359@liondog.tnic


Acked-by: Andy Lutomirski <luto@mit.edu>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>