Use calloc() instead of malloc()
Use calloc() instead of malloc()

This will prevent issues with missing initialisations and also a number of
other issues (delayed OOM conditions, overflows of size_t resulting in too
small allocations) which are however unlikely to occur with the tiny amount of
memory allocated by this program.

sosy-lab/power-gadget_benchexec,sosy-lab/power-gadget_benchexec