prop250: Don't use {0} to init static struct -- causes warning on clang.
See ticket #19132 for the clang/llvm warning.
Since voting_schedule is a global static struct, it will be initialized
to zero even without explicitly initializing it with {0}.
This is what the C spec says:
If an object that has automatic storage duration is not initialized
explicitly, its value is indeterminate. If an object that has static
storage duration is not initialized explicitly, then:
— if it has pointer type, it is initialized to a null pointer;
— if it has arithmetic type, it is initialized to (positive or unsigned) zero;
— if it is an aggregate, every member is initialized (recursively) according to these rules;
— if it is a union, the first named member is initialized (recursively) according to these rules.