Fix various gcc 3.4 complaints.

[David Hampton]

Log Message:
-----------
Fix various gcc 3.4 complaints.

Tags:
----
gnucash-gnome2-dev

Modified Files:
--------------
    gnucash/src/engine/test:
        test-transaction-reversal.c
    gnucash/src/engine/test-core:
        test-engine-stuff.c
    gnucash/src/import-export/hbci:
        gnc-hbci-account.c