powerpc/pseries: Fix formatting to make code look more beautiful

Operators should be separated by spaces in tce_buildmulti_pSeriesLP()

Signed-off-by: Deming Wang <wangdeming@inspur.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220701094553.1722-1-wangdeming@inspur.com