Remove optimization for RAND_poll() failing.
The loop to generate seed data will exit on RAND_status(), so we don't
need to handle the case of RAND_poll() failing separately. Failures
here are rare, so this a code cleanup, essentially.
Daniel Gustafsson, reviewed by David Steele and Michael Paquier.
Discussion: https://postgr.es/m/
9B038FA5-23E8-40D0-B932-
D515E1D8F66A@yesql.se