powerpc/mm: Use mm_is_thread_local() instread of open-coding

We open-code testing for the mm being local to the current CPU
in a few places. Use our existing helper instead.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
4 files changed