Return if DumpKernelStack can't find the kernel stack file.
Return if DumpKernelStack can't find the kernel stack file.

(cherry picked from commit 05c09ece5312ebb4e1c661dde2bbc67798d63f8b)

Change-Id: I78265f13fea936b7fda37e24f9e0999b417fc17a

treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst