test: Correct the random seed log on a prevector test failure

rand_cache is unused since commit
16329224e70d0525208f6b0ba00c5e1531a4f5ea, so it can be removed

rand_seed is wrong since commit
022cf47dd7ef8f46e32a184e84f94d1e9f3a495c, because it is no longer
printing the seed that was used to seed the global random context in
tests. Instead, it prints a (random-ish) value derived from the global
random context via InsecureRand256().

Finally, the for loop creating new prevector_tester objects will always
use the same seed since commit fae43a97ca947cd0802392e9bb86d9d0572c0fba,
because repeated calls to SeedInsecureRand/SeedRandomForTest will always
reseed the global with the same "static const" seed.

Fix all issues by
* removing the unused rand_cache,
* removing the call to SeedRandomForTest which restored the same seed on
  every call in the process, and
* Reseeding the global random context with the (random-ish) rand_seed.

0 files changed, 0 insertions, 0 deletions