hcrypto: Avoid arc4random in kernel
Our HAVE_ARC4RANDOM symbol represents the availability of arc4random()
in userspace, not in the kernel. On Solaris, we'll define
HAVE_ARC4RANDOM, but the built kernel module will be unusable, since
we cannot resolve the arc4random symbol.
To to avoid this, undef HAVE_ARC4RANDOM when building hcrypto for the
kernel, just like we do with HAVE_GETUID.
Change-Id: I17472420b35e7be6b4f698082714c2e51bdb064b
Reviewed-on: https://gerrit.openafs.org/12946
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>