Use unsigned long for prctl argument

uint64_t isn't the right type when running on a 32 bit machine.

BUG=none
TEST=check caps can be dropped on a 32 bit userspace machine like kevin.
minijail0 -u wpa -g wpa -c 3000 -i -t -- /bin/ls

Change-Id: I1ec55dc653fe206a1641f0a971ab2b20c42a2d9c
Signed-off-by: Dylan Reid <dgreid@chromium.org>
1 file changed