This patch fixes MAX_STACK_TRACE_ENTRIES too low warning for ppc32,
which is similar to commit 12660b17.
Reported-by: Christian Kujau <lists@nerdbynature.de> Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Tested-by: Christian Kujau <lists@nerdbynature.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>