Bug 36313: Fix Undefined subroutine &C4::Circulation::CheckReserves error

Bug 36313: Fix Undefined subroutine &C4::Circulation::CheckReserves error

On (at least) git installations of Koha checkouts and checkins fail on
error 500. Logs have following error:

Undefined subroutine &C4::Circulation::CheckReserves called...

Error happens also when one tries to open patrons checkouts from detail page.
Koha doesn't die but table just keeps loading. Solution is to add C4::Reserves
before CheckReserves when it's called from Circulation.pm.

To test:
1. Apply this patch.
2. Try to check out and check in item.
=> Confirm both operations are succesfull.
3. Attempt to open patrons checkouts from patron detail and checkout page.
=> Table should load

Also prove t/db_dependent/Circulation.t.

Sponsored-by: Koha-Suomi Oy
Signed-off-by: BabaJaga <babajagawgoglach@gmail.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>