Revert "Fix "pg_ctl start -w" to test child process status directly."

Revert "Fix "pg_ctl start -w" to test child process status directly."

This reverts commit c869a7d5b44e7164fadfb638786def05d510312a.
As pointed out by Maksym Sobolyev in bug #14199, that approach doesn't
work if the postmaster forks itself an extra time due to silent_mode
being enabled.  We removed silent_mode in 9.2, so the pg_ctl change is
fine in 9.2 and later, but it fails when that option is enabled in 9.1.
Seeing that 9.1 is close to end-of-life, let's adopt the most conservative
fix we can, which is to revert the pg_ctl change in the 9.1 branch.

Discussion: <20160618042812.5798.85609@wrigleys.postgresql.org>