Trusty wants to seed from a different RNG than the one that supplies
per-draw entropy. This is a no-op change unless you're substituting in
your own implementations of these functions.
To see that it's a no-op in urandom.c, note that it only changes the
|seed| argument to |fill_with_entropy|. That causes the value of
|extra_getrandom_flags_for_seed_bss_get| to be ORed into the flags,
but that value will always be zero unless it's an Android FIPS build.
Change-Id: Ic8d954df3074559cbf1bfee1ae91a4a2b7e14d9d
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/48485
Reviewed-by: David Benjamin <davidben@google.com>