Bug 14538: editing perl doc for CalcFine

Bug 14538: editing perl doc for CalcFine

To Test:
Read perldoc C4/Overdues.pm
Confirm that it says CalcFine returns four values and that rest of the documentation is correct

NOTE: only a little visual ugliness, but definitely an improvement.

Signed-off-by: Mark Tompsett <mtompset@hotmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Jesse Weaver <jweaver@bywatersolutions.com>
(cherry picked from commit f1bbc3d2a1c177847f7d34c9d2be771bd5fa03e8)
Signed-off-by: Julian Maurice <julian.maurice@biblibre.com>