powerpc/pseries: use memdup_user_nul

Use memdup_user_nul() helper instead of open-coding to simplify the code.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Geliang Tang 2017-04-29 09:45:15 +08:00 • committed by Michael Ellerman
commit 3783225130