pgsql: Now that pg_upgrade uses -w in pg_ctl, remove loop that retried

Now that pg_upgrade uses -w in pg_ctl, remove loop that retried testing
the connection;  also restructure the libpq connection code.

This patch also removes the unused variable postmasterPID and fixes a
libpq structure leak that was in the testing loop.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/6c4d2bd9141034bd27977794f52003fd6f7d01f0

Modified Files
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contrib/pg_upgrade/pg_upgrade.h |    1 -
contrib/pg_upgrade/server.c     |  165 +++++++++++----------------------------
2 files changed, 47 insertions(+), 119 deletions(-)