[PATCH] ppc64: Fix return value of some vDSO calls

The ppc vDSO would not properly clear the return value for some calls,
which will be a problem when interfacing those calls with glibc. This
should be fixed before 2.6.12 is released (as it is the first kernel
with the ppc vDSO) so that we don't have to play with symbol versioning
and ugly workarounds.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>