Bug 19899: Restore Item floats feature - do not crash

Bug 19899: Restore Item floats feature - do not crash

Error is "The method noreturn is not covered by tests!"
caused by commit 6eade474ed3a84a5ba372a26ac27bf9fb4bd2299
Bug 18276: Remove GetBiblioFromItemNumber - Easy ones

When the "Return policy" (var returnbranch) is set to "Item floats" (value noreturn)
the library must be the current library (from userenv).
This behaviour is used in C4::Circulation::AddReturn

On bug 18276 I assumed that the value was either holdingbranch or
homebranch, and forgot it could be "noreturn"

Test plan:
Set Return policy to Item floats
Check an item in
=> without this patch it explodes
=> With this patch applied it will check the item in

Signed-off-by: Mohd Hafiz Yusoff <mhby87@gmail.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>