Bug 20598: (QA follow-up) Tiny fixes

Bug 20598: (QA follow-up) Tiny fixes

[1] Correct POD for _FixOverduesOnReturn
Is called by AddReturn, AddRenewal and LostItem.
Also tested in Circulation.t btw

[2] $dbh is not used in _FixOverduesOnReturn
[3] Moving all parameters to the first line.
[4] Variable $uquery is not used too.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
(cherry picked from commit 867f88076eb47c434c3edf6f7903238b5a465cdb)
(cherry picked from commit 2c7717546705d2bebcaed3cc43e6cf6f48359c4a)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>