Bug 26132: (follow-up) Fix broken code in TooMany function

The $checkouts variable was not defined in the PatronLibrary case at
all and in the else case the SQL join was totally missing.

To test:
1) Without this patch notice prove
   t/db_dependent/Circulation/TooMany.t fails
2) With this patch notice prove
   t/db_dependent/Circulation/TooMany.t succeeds

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>

C4/Circulation.pm

@@ -543,10 +543,11 @@ sub TooMany {
             $checkouts = $patron->checkouts->search(
                 { 'me.branchcode' => $branch} );
         } elsif (C4::Context->preference('CircControl') eq 'PatronLibrary') {
-            ; # if branch is the patron's home branch, then count all loans by patron
+            $checkouts = $patron->checkouts; # if branch is the patron's home branch, then count all loans by patron
         } else {
             $checkouts = $patron->checkouts->search(
-                { 'item.homebranch' => $branch} );
+                { 'item.homebranch' => $branch},
+                { prefetch          => 'item' } );
         }
 
         my $checkout_count = $checkouts->count;