powerpc/64s: remove unneeded semicolon

Eliminate the following coccicheck warning:
./arch/powerpc/platforms/powernv/setup.c:160:2-3: Unneeded semicolon

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1612236877-104974-1-git-send-email-yang.lee@linux.alibaba.com