Bug 6315: Fix depreciated constructions in C4::Serials

Bug 6315: Fix depreciated constructions in C4::Serials

Perl 5.14 will issue warnings in cases where it is assumed that
() will magically appear around qw() as the interpreter
will stop fooling itself that they are there
Added the missing () in the couple of cases they were required

Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
Signed-off-by: Ian Walls <ian.walls@bywatersolutions.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
(cherry picked from commit 968a6af37dd3472b7417bfa694bf6cf3b75e1713)

Signed-off-by: Chris Nighswonger <chris.nighswonger@gmail.com>