Fixes ValveSoftware/halflife#1536

This is merely to keep the VC++ Debug builds happy and addresses cases
where variables were being used without being initialized. There should be
no visible changes apart from non-functional side effects to the users of
Release builds.
Thanks to @fabiosarts for finding and reporting these problems.
Thanks to @LevShisterov for suggesting how to fix geiger.cpp files, which I
followed closely except using <= 800 instead of < 800.