Bug 21628: Simplify holds awating pickup report

Bug 21628: Simplify holds awating pickup report

To test:
1 - Place a number of holds
2 - Check in the items and confirm the holds
3 - Visit /cgi-bin/koha/circ/waitingreserves.pl
4 - View the report
5 - Apply patch
6 - Confirm that the report looks the same
7 - Confirm cancelling holds works as before

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Followed test plan, patch worked as described
Signed-off-by: Alex Buckley <alexbuckley@catalyst.net.nz>
Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>