linux-phytec-fsl

powerpc: Improve comment explaining why we modify VRSAVE

The comment explaining why we modify VRSAVE is misleading, glibc
does rely on the behaviour. Update the comment.

Signed-off-by: Anton Blanchard <anton@samba.org>
Reviewed-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>