pgsql: Revert "Fix isolation test to be less timing-dependent"

Revert "Fix isolation test to be less timing-dependent"

This reverts commit 2268e6afd596.  It turned out that inconsistency in
the report is still possible, so go back to the simpler formulation of
the test and instead add an alternate expected output.

Discussion: https://postgr.es/m/20180103193728.ysqpcp2xjnqpiep7@alvherre.pgsql

Branch
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REL_10_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/a6565da8b9ef2b900d298a19cb817a2c9ca90f7e

Modified Files
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src/test/isolation/expected/multiple-cic.out   | 15 +++++----------
src/test/isolation/expected/multiple-cic_1.out | 20 ++++++++++++++++++++
src/test/isolation/specs/multiple-cic.spec     | 12 ++++--------
3 files changed, 29 insertions(+), 18 deletions(-)