pgsql: Correct sundry errors in Hot Standby-related comments.

Log Message:
-----------
Correct sundry errors in Hot Standby-related comments.

Fujii Masao

Modified Files:
--------------
    pgsql/src/backend/access/transam:
        xact.c (r1.295 -> r1.296)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/xact.c?r1=1.295&r2=1.296)
    pgsql/src/backend/storage/ipc:
        procarray.c (r1.72 -> r1.73)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/ipc/procarray.c?r1=1.72&r2=1.73)
        standby.c (r1.27 -> r1.28)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/ipc/standby.c?r1=1.27&r2=1.28)
    pgsql/src/backend/tcop:
        postgres.c (r1.595 -> r1.596)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/tcop/postgres.c?r1=1.595&r2=1.596)
    pgsql/src/include/access:
        xlog.h (r1.115 -> r1.116)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/access/xlog.h?r1=1.115&r2=1.116)
    pgsql/src/include/catalog:
        pg_control.h (r1.57 -> r1.58)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_control.h?r1=1.57&r2=1.58)