Bug 41475: Make hostitemnumbers an array ref

To test:

1. Set 'EasyAnalyticalRecords' to 'Show'.
2. Find or create a parent record that has at least 2 items on it. Note the itemnumbers and the framework.
3. Edit that framework so you can add a 773$0, 773$9, and 773$t
4. Find or create a child record.
5. Make at least 2 773 entries on the child record. Add the biblionumber of the host record to the 773$0.
6. In each entry for the 773$9 add one of the itemnumbers from the host record.
7. For the 773$t and the biblio title of the host record.
8. Save.
9. Now attempt to put a hold on the child record.
10. 500 error:
11. APPLY PATCH and restart_all
12. Try placing the hold again, this time it succeeds.

Signed-off-by: Emmi Takkinen <emmi.takkinen@koha-suomi.fi>
Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
(cherry picked from commit d2a3fe93f2)
Signed-off-by: Jacob O'Mara <Jacob.omara@openfifth.co.uk>

C4/Reserves.pm

@@ -430,7 +430,7 @@ sub CanBookBeReserved {
             {
                 -or => [
                     biblionumber => $biblionumber,
-                    itemnumber   => { -in => @hostitemnumbers }
+                    itemnumber   => { -in => \@hostitemnumbers }
                 ]
             }
         );