[PATCH] iphlpapi: Avoid use of uninitialized variable

[Huw Davies]

On Thu, Jan 27, 2022 at 11:18:53PM +0100, Gerald Pfeifer wrote:
> In gateway_and_prefix_addresses_alloc prefix_len isn't set in the
> error case, but used unconditionally. Avoid this by initializing
> upon declaration.
> 
> (Identified by GCC 12.)

It's actually not used unconditionally, since it's only used if
sockaddr.si_family is non-zero, in which case it will have been
initialised.

It makes more sense to zero-init where sockaddr in also initialised
since we're in a loop.

I've sent in v2.

Huw.