ppc: Avoid a warning with the next patch

When the code is moved together by the next patch, compiler
detects a possible uninitialized variable use. Avoid the warning
by initializing the variables.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
