Bug 19945: (follow-up) optimization and test correction

Bug 19945: (follow-up) optimization and test correction

The double call to CanItemBeReserved was pointless in
the C4/Reserves.pm HoldItem, as CanBookBeReserved calls
CanItemBeReserved and even returns that code.

Additionally, the tests failed, because there were 5
tests not 4.

TEST PLAN
----------
prove t/db_dependent/ILSDI_Services.t
run koha qa test tools

Signed-off-by: Mark Tompsett <mtompset@hotmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>