pgsql: Remove some unnecessary tests of pgstat_track_counts.

Remove some unnecessary tests of pgstat_track_counts.

We may as well make pgstat_count_heap_scan() and related macros just count
whenever rel->pgstat_info isn't null. Testing pgstat_track_counts buys
nothing at all in the normal case where that flag is ON; and when it's OFF,
the pgstat_info link will be null, so it's still a useless test.

This change is unlikely to buy any noticeable performance improvement,
but a cycle shaved is a cycle earned; and my investigations earlier today
convinced me that we're down to the point where individual instructions in
the inner execution loops are starting to matter.

Branch
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master

Details
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http://git.postgresql.org/gitweb?p=postgresql.git;a=commitdiff;h=f4d242ef94730c447d87b9840a40b0ec3371fe0f

Modified Files
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src/backend/postmaster/pgstat.c | 8 ++++----
src/include/pgstat.h | 14 +++++++-------
2 files changed, 11 insertions(+), 11 deletions(-)