minigbm: cros_gralloc: Fix type mismatch on 64-bit builds

minigbm: cros_gralloc: Fix type mismatch on 64-bit builds

For some reason GCC does not like using %llu print format for uint64_t, which
maps to unsigned long on Linux x86_64. However on Linux i386 unsigned
long is a 32-bit type and uint64_t maps effectively to unsigned long
long and we need to use %llu. To work this around, simply cast the value
to unsigned long long.

BUG=b:36540057
TEST=emerge-reef arc-cros-gralloc with multilib patches applied

Change-Id: Ic585d40d690346babc280a04111fc8aedf8a30cd
Reviewed-on: https://chromium-review.googlesource.com/487766
Commit-Ready: Tomasz Figa <tfiga@chromium.org>
Tested-by: Tomasz Figa <tfiga@chromium.org>
Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>