Bug 37076: Fix incorrect needsconfirmation code

Bug 37076: Fix incorrect needsconfirmation code

This patch corrects two instances of RESERVED_WAITING to RESERVE_WAITING

Test plan:
1) Navigate to system preferences and search for AllowItemsOnHoldCheckoutSCO
2) Observe from the description that the correct status code is RESERVE_WAITING
3) Search the repository for RESERVED_WAITING - you should find two instances, one in Checkouts.pm and one in checkout.js
4) Apply patch
5) Repeat step 3 - there should be 0 instances

Signed-off-by: Lucas <lchirlias@ville-roubaix.fr>
Signed-off-by: Emily Lamancusa <emily.lamancusa@montgomerycountymd.gov>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>