ion: Don't free memory if unsecure fails

If unsecure fails, this means the CPU cannot touch the
physical memory. This means if the memory is freed back to
the buddy allocator all accesses will trigger faults. If
unsecure fails, the only option is to leak the memory and
not free it.

Change-Id: I6a98761912598a9f8cdcc3914eca8e5e41147e55
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>