#81 spicious warning

[Dietmar Warning]

Giles -do you have an idea?
Got this in VS:
9>C:\msys64\home\warning\ngspice\src\frontend\breakp.c(315): warning C4701: potentially uninitialized local variable 'td' used
9>C:\msys64\home\warning\ngspice\src\frontend\breakp.c(315): warning C4703: potentially uninitialized local pointer variable 'td' used

[Giles Atkinson]

It looks like a false positive, and gcc does not report it. But adding a harmless initialisation should silence it.