powerpc: Remove redundant spaces to match coding style

These one line of code don't meet the kernel coding style, so remove the
redundant space.

Signed-off-by: maqiang <maqianga@uniontech.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210303115710.30886-1-maqianga@uniontech.com