pgsql: Remove unnecessary checkpoint from PL regression tests.

Log Message:
-----------
Remove unnecessary checkpoint from PL regression tests.  This was once
handy to prevent core dump files from disappearing, but it's useless now
because (a) we don't drop core in individual DB subdirectories anymore,
and (b) CREATE DATABASE forces an internal checkpoint anyway.

Modified Files:
--------------
    pgsql/src/pl/plperl/expected:
        plperl.out (r1.10 -> r1.11)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/pl/plperl/expected/plperl.out.diff?r1=1.10&r2=1.11)
    pgsql/src/pl/plperl/sql:
        plperl.sql (r1.12 -> r1.13)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/pl/plperl/sql/plperl.sql.diff?r1=1.12&r2=1.13)
    pgsql/src/pl/tcl/expected:
        pltcl_setup.out (r1.6 -> r1.7)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/pl/tcl/expected/pltcl_setup.out.diff?r1=1.6&r2=1.7)
    pgsql/src/pl/tcl/sql:
        pltcl_setup.sql (r1.5 -> r1.6)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/pl/tcl/sql/pltcl_setup.sql.diff?r1=1.5&r2=1.6)