LP1895660: Silence Perl Warnings

LP1895660: Silence Perl Warnings

There are many perl warnings in make check and the day-to-day
logs when using Evergreen. This branch aims to address the
warnings and to make reviewing easier each file will be
individually committed with a small rationale for the changes
though it is assumed that this branch will be largely squashed
away if / when committed.

Booking.pm: Possible precedence issue with control flow operator
The precedence of 'or' is significantly lower than '||', so much so
that it can be less than the precedence for assignments.
Replace 'or' with '||' since they're equivalent in this case anyway,
and also add parens for flavor.

Signed-off-by: Jason Boyer <JBoyer@equinoxinitiative.org>