Bug 29474: Remove one layer of indendation by adding if check in the begginning

Bug 29474: Remove one layer of indendation by adding if check in the begginning

If we simply return "no" immediately from the function when the
checkout is not an autorenewed checkout we can drop one layer of
indendation and the code becomes much easier to read.

To test:
 1) prove t/db_dependent/Circulation.t

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>